Theme Music Power-Up

""64. When your show's opening theme song starts to play, your enemies are fucked.""

- The Laws of Super Robot Anime

A character's strength and abilities are directly proportional with how cool their personal theme music is. The more suddenly it starts up and the louder it is, the more butt-kicking is about to commence. This applies to both heroes and villains and is a power that the Badass Normal is allowed to use. Alternatively, the music is a representation of the character getting into "the zone".

Video games will sometimes have a variation of this, where a specific jingle plays during temporary power-ups, like invincibility due to an Invincibility Power Up; see Power Up Motif.

If a Theme Music Power-Up is defeated, then it's The Day the Music Lied. If it's in particularly spectacular fashion, it may end with a Record Needle Scratch or by Letting the Air Out of The Band (or, if you're really unlucky, a Last Note Nightmare).

Ominous Latin Chanting, the One-Woman Wail or the Cherubic Choir are popular choices for this, as are a techno beat or heavy metal riff.

Sometimes near the end, the series Theme Song will play, allowing every good guy to kick some major rear at the Grand Finale. This is a Last Episode Theme Reprise.

Compare Autobots Rock Out, Most Wonderful Sound, Power-Up Motif, and Music for Courage.

Anime & Manga

 * Kara no Kyoukai has Shiki's unofficial theme "Seventh Heaven" played several dozen times over the course of the series, but it gets kicked up a notch or two for her fight scenes.
 * The Slayers: Lina has the same music anytime she casts Dragon Slave (and Giga Slave and Laguna Blade). Also somewhat distorted on the Battle Music (same everytime -- ikinashi oodate) and totally distorted for Amelia and Gourry (with douchuuki).
 * Slayers Evolution-R has a variation on the "series theme plays as Big Bad gets ass handed to him" thing, playing the theme from Next.
 * Usagi of Sailor Moon had several theme songs based on The Power of Friendship. The Outer Senshi have their own Rule of Cool music.
 * A bit different in the final season, in which the new addition to the cast -- the Sailor Starlights -- had an appearance theme very different to the traditional "sudden and loud" ones: starting quiet and subtle and then getting louder during the close-up on them.
 * The English-dubbed version of the Season 1 finale features "Carry On" during the final battle, one of the very few improvements over the Japanese original (the original used the full-length opening song "Moonlight Densetsu"). Other songs featured are "Ai no Senshi", "La Soldier" (from the Sailor Moon R finale), and "Moon Revenge" (from the R movie). The last episode of Sailor Stars uses the season's opening "Sailor Star Song" in this manner.
 * Ichigo of Bleach; whenever he was about to kick serious ass, his Image Song ("Number One" by Hazel Fernandez) would kick in. This was subverted at one point: Ichigo moves to attack an unusually powerful badass, and his Theme Music Power Up stops almost as soon as it starts when his opponent blocks the attack with a single finger. Yeah, that's right... is so tough he can even defeat your theme music.
 * As this video shows, "Number One" did provide a Theme Music Power Up, but for the wrong character. "Number One" allows Renji to display some awesome, but as soon as Ichigo jumps into action, the fickle theme song is cutdown by 's finger of doom.
 * Ironically, the first proper use of the Image Song in the series was when it was used by the series' Fake Ultimate Hero to rescue Ichigo with his "Ultimate Attack".
 * More recently, the Big Bad and/or his Arrancar get classy, suspenseful Latin-style music in the background whenever they're making a grand entrance or are about to kick big-time ass. (This is in keeping with their Spanish-tinted theme.)
 * It's rather sad that it's been over a year since Ichigo has managed to have a proper theme music power-up. And he's the main character!
 * No fear, his theme song is back in full form right before the Ulqi fight.
 * Number One returns in a rock form called Chokkaku when Ichigo returns from his little training exercise in the Dangai.  It's safe to say its power returned.
 * Guilty Crown does this when the main character gets his powers at the end of the first episode, with a song called Bios, composed by the wildly popular J-Pop band Supercell and sung in Gratuitous German. Don't let the mangled pronunciations get you; it's only because the singer is Japanese. Take a good look at the actual lyrics and you'll see that not only is the German grammar flawless, but the lyrics also allude to the ordeals the characters in the actual show face. As of winter 2011, there were also several cases of Autobots Rock Out, and at that point the show was only halfway through season one.
 * Kirika and Mireille of Noir. SALVA NOS, DEUUUUUS!
 * One shot even has Kirika wait to shoot the guy until the music finishes.
 * Similarly, anytime you start to hear Yanmaani (the song's title is "Nowhere") in the background in Madlax, the titular character is about to kick serious amounts of ass with inhuman skill. It's so prevalent that The Other Wiki even mentions it. It is a joke among fans that the word gives Madlax super powers.
 * The Twelve SISTERs of Coyote Ragtime Show.
 * The climax of the Galaxy Angel games always follows the Theme Song variant, playing that year's version of Eternal Love (or, in Galaxy Angel II games, Wing of Destiny).
 * Saiyuki has the OP theme "For Real"; it's not surprising that the rockin' guitar version brings the pain to you, but what's more interesting is that the gentle, tinkling piano version can either be the theme to character growth and introspection... or the warning that Genjo Sanzo is about to deliver a No Holds Barred Beatdown on whoever's in his way -- complete with some snarky deconstruction of whatever BS the poor yutz was trying to spout at the time.
 * Yu-Gi-Oh! has the show's main theme begin to play pretty much every time Yugi pulls off an epic combo. The theme of the Egyptian God cards plays whenever one of them is summoned.
 * In the first season's English dub, Kaiba's theme, "I'm Back," plays in a few choice Theme Music Power Up spots.
 * During episodes 18 and 19 of the GX dub, the duelist who purloined Yugi's deck and was dueling Jaden kept having musical overtures from the previous series playing. Towards the end, they were even being played in the same musical style as a lot of GX music.
 * Yu-Gi-Oh 5 Ds has a variety, kicking off with Jack Battle in the very first episode when he summons Red Demons in a televised duel, then got upgraded to an early and unreleased track when summoning Savior Demon Dragon that goes under the Fan Nickname Jack Battle 2. Yusei has his own themes, Yusei Battle 2 usually reserved for whenever he whips out Savior/Star Dragon. As of late, with Accel Synchros coming into play, a couple of occasions featuring Yusei summoning Shooting Star Dragon are accompanied by Clear Mind sung by Masaaki Endoh.
 * Dokkoida?! hangs a Lampshade on this; the hero's power suit is able to induce this state by playing a heroic theme song. At least if the company that made the suit actually got that feature working before they released it. But the hero doesn't know that, and he manages to get the same effect just from suggestion and enjoying the Hot Blooded music.
 * Pretty much every evolution sequence in every season of Digimon adheres to this trope. The more absurdly powerful the evolved form is, the more obnoxious and high-pitched the theme music will be, whereas less impressive evolutions (compared to the one available to the main character's partner at any given point in the series) often go by without music altogether. Also, true to this trope, evolution music invariably stops as soon as the evolved Digimon is hit by it's enemy.
 * A good example occurs in the Adventure movie, Bokura No War Game. The evolution song, 'Brave Heart', plays throughout one of the battle scenes, and when Patamon tries to digivolve to his Adult/Champion level, he is attacked, at which point the music cuts out suddenly. It resumes around 30 seconds later when Taichi and Yamato's Digimon charge to counter attack. And then, before the computer crashes on Taichi, the line 'SHOW ME YOUR BRAVE HEART!' skips and replays several times, cutting out when the computer gets the BSoD.
 * Another example of the above happens in the episode where Greymon dark digivolves into SkullGreymon. During the battle scene, Brave Heart plays as normal, but a few seconds into the evolution scene, the song fades into a really dark and sinister piece of BGM.
 * Digimon Savers adheres doubly so. There's a set of leitmotifs for various stages of evolution, but whenever the J-Rock theme tune "Believer" cues up, you know the Monster of the Week is about to get beaten in a spectacularly flashy, Hot Blooded manner. Sadly, due to the song being Japanese and the dubbing company having a music budget of about a nickel, it was cut in the domestic release, replaced with the more standard evolution leitmotifs.
 * Sadly? While Believer is great, I absolutely love Thorsten Laewe's soundtrack for the series! I think he did an excellent job with the occurrences of this trope.
 * And in Adventure, we have "Hey Digimon". It plays, then you're screwed.
 * The American Digimon movie had a fairly good example in the first half. after the swarm of Diaboromons blast Wargreymon and Metalgarurumon into submission, the scene where the two digimon fuse into Omnimon was accompanied with a Spine Chilling rendition of the Digimon theme. However, the movie took a different route with the actual fight scene, which was treated to a ear-rendingly bad licensed pop-rock song that is completely at odds very different but still equally good song that still fits with the Curb Stomp Battle being shown.
 * Another The Movie dub example: the fight between Parrotmon and Greymon. 15 minutes in and with only a narmy rap remix of the theme heard so far, Greymon introduces himself to Tai. The distant sound of records scratching echoes across the 5.1, and three glorious almost-words, despite being only whispered, are still louder than the biggest explosion: "DI- DI- DI-..."
 * From the same fight, after Greymon blacks out (Parrotmon is a level higher than Greymon, so he's having some trouble) Tai uses the whistle to wake him up for round two. We don't hear too much of the song, as round two is much shorter.
 * Four words: We Are Xros Heart! (even a version X7!), Evolution and DigiXros Taiki (or Kiriha)! When that music plays, you know someone is going to curbstomp something.
 * Cardcaptor Sakura seems to have a Leitmotif that appears on the soundtrack whenever she finally joins battle with a particularly powerful enemy. (If you've seen the show, you'll recognize it as a disco-style instrumental with oddly majestic sweeping strings playing the melody.)
 * Various versions of a heavy, hot-blooded rap song are played during pivotal power-up moments in Tengen Toppa Gurren Lagann. Eventually they get so powerful that they actually get those lyrics superimposed on an opera track.
 * Tengen Toppa Gurren Lagann plays this down to the very basis of each part of the trope. There's the various power-up versions of 'Rap Is A Man's Soul!'(AKA 'ROW ROW FIGHT DA POWAH') One for Kamina, one for, and "Libera Me From Hell". Along with these are 'Ten Wo Tsuke/Pierce the Heavens With Your XXX!' (Occurs in Episodes 1 and 8, when they first break through to the surface and the first Giga Drill Breaker), "Happily Ever After" (Insert Song, used in Episode 11 when Simon has his famous He's Back moment), and the full version of the show's theme, Sora Iro Days, used when
 * Also works for the bad guys: whenever Viral shows up and does something awesome, the Surprisingly Good English song "Nikopol" plays.
 * And then he gets beaten EVERY.SINGLE.TIME. Which is really ironic considering the meaning of the title Nikopol coming from the greek as Nikê meaning victory and polis which is city. City of victory? And the guy gets beaten all the time...
 * Subverted in episode 25 where an attack is launched, a power up song starts... and the missile is harmlessly crushed before it can reach its destination. In all fairness, that wasn't the main theme song anyway.
 * Then played straight immediately after.
 * In episode 2, when Kamina and Simon hijack the Gunzan, later named Gurren, the Surprisingly Good English song "Gattai Nante Kusokurae" (AKA "To Hell with Gattai") starts playing.
 * It plays during the final battle with Lordgenome as well, when Simon is reduced to fighting the Spiral King's Gurren Lagann-style mech with just his own Lagann, and totally kicks ass.
 * During the final battle with the Anti-Spiral in the second movie, a new version of Sora Iro Days plays. It blows away the series final battle in sheer awesomeness and badassery, and must be seen/heard to be comprehended.
 * Futari wa Pretty Cure: Nagisa and Honoka are undefeatable when the instrumental version of the theme song is playing. And if the background music has lyrics, they can accomplish miracles like defeating Jaaku King or getting Kiriya to turn good. At the end of Futari Wa Pretty Cure Max Heart,.
 * The All Stars Deluxe movie does this a total of four times. It happens once for each of the teams that had already finished their seasons, and after this, the main theme of the movie plays for the final group attack.
 * Heartcatch Precure has "Heart Goes On" for its big moments. However, the first time it was played, it was rather tame - a combined musical concert and fashion show. The next two times it's played it's played straight.
 * Konjiki no Gash Bell brings a quite literal example of this trope. Italian Super Star Parco Folgore has a hit song known as "Muteki Folgore" (Invincible Folgore) with the ability to revive him every time he has been knocked down if it is sung by his partner Kanchome.
 * The first season theme of Hajime no Ippo often plays during Ippo's final drive to victory in a given match.
 * Subverted in one episode where during Ippo's first match against Japan Featherweight Champion Eiji Date, it is suddenly interrupted by Eiji's counter punch.
 * The song Inner Light, the opening for that season, begins to play in full Ippo begins his final counterattack against Sendou during the Japanese Featherweight Championship, when he pulls off his newly completed Dempsey Roll for the first time.
 * When you hear Fate's voice actress, Nana Mizuki, start to sing her insert song for that season of Magical Girl Lyrical Nanoha, expect every villain currently on screen to have their asses handed to them within the next five minutes. Fate gets a particularly big one of these in the form of the awesome "Pray" during the final showdown with Jail Scaglietti and the Numbers.
 * Similarly, Nanoha gets an awesome variation during her fight with Quattro. As Nanoha's Area Search finds Quattro, the background music shifts from Quattro's synth-organ Leitmotif to Nanoha's "Ace of Aces" battle theme
 * The aptly named "Shooting time" signals when a hero gets up, sometimes after a memory or speech, and lays the smackdown on one of the villans, preferably with a Wave Motion Gun.
 * Likewise, whenever "Meteor" or "Vestige" play in Gundam SEED or Gundam SEED Destiny, expect Kira Yamato to appear and disable the entire opposition without a scratch.
 * When Cagalli shows up in the Akatsuki to help defend ORB from the ZAFT attack in Destiny and the song "Honoo no Tobira" plays. Basically, the ORB forces go from on the ropes to fighting chance,
 * G Gundam had two themes dedicated to Domon's Finishing Moves, "Moegare Toushi" for the Shining Finger and the other "Waga Kokoro, Meikyo Shisui" for just about anything God Gundam did.
 * Many of the tracks of Eureka Seven are meant just as a theme music power up, be it for the heroes or the villains. Whenever Renton does anything especially awesome, a song insert, "Storywriter" begins playing.
 * The first opening song, "Days", also lends itself to a Theme Music Power Up for Renton and Eureka in episode 32.
 * This was also done by Neon Genesis Evangelion. Whenever EVA-01 is about to kick some ass and tear some unfortunate Angel a new one, either The Beast or The Beast II plays. The Beast II is even used for such moments in the crossover Super Robot Wars games. Also, in the series' original Mind Screw happy ending, when Shinji realizes his whole life doesn't need to revolve around piloting EVA-01 and he can live a happy life without it, two versions of the show's theme "A Cruel Angel's Thesis" are played, a strings version, The Heady Feeling of Freedom, and a piano and guitar version, Good, or Don't Be, in succession.
 * Rebuild gives Shinji his own Theme Music Power up with Sin From Genesis, a remix of Beast II that plays over his
 * The James Bond-ish opening theme tune in Read or Die kicks up at the end of the first episode of the OVA, when Yomiko and Nancy square off against Otto Lilienthal and his transforming glider.
 * And whenever you hear it fire up during the sequel, strap in tight, because someone's about to kick some major ass.
 * Plenty of instances in Naruto:
 * In part I, the titular character had several "commence recovery and ass-kicking" tunes. "The Raising Fighting Spirit" was the most common, but several were held in reserve for really stand-out occasions. To beat Neji, Naruto had to bust out three of these in a row ("Avenger" followed immediately by "Heavy Violence" followed immediately by "Strong and Strike").
 * Rock Lee has "Utsukishi Aoi Yajuu" (Beautiful Green Beast), which starts up every time it seems like he is going to win a battle.
 * Shikamaru has the techno song "Fake" which starts up whenever it turns out things have gone All According To Plan.
 * In part I, whenever Orochimaru's theme music started playing the other guy was screwed. The normal version meant they were merely scared half to death and weren't going to dare stand up to him; the "fight" version was reserved for horrible Curb Stomping.
 * Seras Victoria transforms into a Draculina and tears through her enemies as Suilen's beautiful, haunting 'Zakuro' plays in the background.
 * In Dragonball Z, when Cell goads and torments Gohan to transcend his Super Saiyan power, Gohan does exactly that, to a tune called "Demon vs. Demon" (in some translations). A fitting name, considering what Gohan basically becomes in this state. An alternate translation is "Spirit vs. Spirit"; the concepts aren't as different in Japanese as in English, but both translations fit the scene pretty well.
 * In addition, in the dub of Dragonball Z there's a theme that plays for Goku during his first Super Saiyan 3 transformation. This music is also played during the entire Majin Buu saga whenever one of the heroes does something awesome.
 * On top of that, Vegeta got such an awesome song that when I downloaded it from iTunes, it was the second-best selling Bruce Faulconer song, after the main theme. (March 2009) Oddly enough, it's called "Vegeta Super Saiyan", even though he's not always Super Saiyan when it's playing.
 * This is because Vegeta transforming to fight #19 was the scene that introduced the song
 * It should be noted that Trunks previously had two insert songs, one of them used for his first Super Saiyan Transformation against Freeza.
 * Dragon Ball Kai is no stranger to this, bringing in all kinds of new songs for old characters. In particular, Vegeta gets his own insert song while powering up against Freeza, and Trunks who is definitely no stranger to insert music gets a whole new theme titled "Tatta Hitori no Senshi" for his powerup against Cell, even if it does end up a Curb Stomp Battle in Cell's favor, it's still a pretty badass song. It should be dually noted that both songs are sang by the person's respective seiyuu.
 * The Shakugan no Shana cast get one in the climax of the fight against in Season 2.
 * This happens in Death Note whenever Light reveals whatever Xanatos Roulette he has cooked up that week, just in case we had forgotten what a Magnificent Bastard he is.
 * Likewise, whenever L really gets going, his guitar theme music flares up to match.
 * "Little Busters" fills this role several times in FLCL, usually when it plays during a Naota/Canti gattai.
 * In Katekyo Hitman Reborn, there is separate theme music for "Look, someone (usually Tsuna) is no longer failing at life!" and "Oh, by the way, I acquired some new way to kick your butt. SORRY FOR NOT TELLING YOU!" ... as well as everything else, to the extent that it's possible to tell what's going on just by listening to the background music.
 * To be more precise, the songs are called "Shinuki Time!", "Succession", "Hibari's Theme" and "Tsuna Awakens", respectively.
 * Both played straight, and played very straight by Gao Gai Gar. When Masaaki Endoh shouts "GA-GA-GA GA-GA-GA-GAOGAIGAR!", it's fair warning that Guy's power of raw courage is about to rip you apart. Meanwhile, Mic Sounders the 13th has a couple of songs on Disc P that literally power up any protagonist robot in earshot, restoring their energy and galvanizing their fighting spirit.
 * Also, there are separate themes for the titular mecha's two big finishers, Hell and Heaven and the Goldion Hammer. Also, the rest of GGG's mecha get an extremely hot-blooded theme of their own when they're about to do some pretty awesome stuff.
 * The latter is heard most notably when they assault the Contra Fall, and is titled after the entire Mobile Unit: "Strongest Brave Robo Corps". There's also the J-Ark's save-the-day tune "Beautiful Wings Of Light", and the ominous guitar riffs during the opening of the Zonuda battle
 * Gao Gai Gar FINAL has this in spades, when Chouryujin and Gekiryujin are preparing to fight against their respective Soul Master counterparts the theme Saikyo Yuusha Robo-Gundan plays.
 * Mic Sounders 13 gets this as well as when he first fights his Soul Master counter part he invokes Disk F playing Let's Final Fusion to attack with a Golden GaoFighGar MADE OF ROCK,
 * Koryu and Anryu also get a similar moment when they  to take on their Soul Master Counterpart, the song, Saikyou Yuusha Robo Gundan Ladies
 * Don't forget Yuuki aru Tatakai. When this piece starts, no one will survive from Guy's attacks. NO EXCEPTIONS. Example.
 * The Pokémon anime usually has one of the openings or upbeat endings accompany a sudden comeback (maybe even a whole battle) or evolution. "Pokémon Symphonic Medley" has been common recently, as there is no full version of the song.
 * In older seasons, they'd use this awesome electric guitar remix of the Gym theme.
 * Late in the Japanese version of the Advanced Generation series, Battle Frontier would usually start playing when Ash begins to make a comeback. Late Diamond & Pearl episodes were fond of throwing in Saikou - Everyday! in the same situation.
 * The dub did this a couple times, as well. In the match against Roark, the English Diamond & Pearl theme played. During a Contest with Dawn's rival Ursula, they played Battle Frontier (replacing the line "It's the Battle Frontier!" with "Let the battle begin!"), and the final DP episode had We Will Carry On! syncing up to the Flint vs Cynthia battle.
 * Almost the entire last episode of Stellvia of the Universe is accompanied by various theme music pieces, including the OP. The sheer awesome of its Grand Finale takes more than words to convey.
 * Stellvia actually uses its opening theme like this several times in the series...and the first time, it even gets subverted.
 * Gravion has a theme song that plays when it combines, in one episode Sandman and the maids powered the robot up by singing karaoke!!!
 * Sol Gravion has its own theme towards the end of Gravion Zwei. The names are Gasshin! God Gravion and Enou Gasshin! Sol Gravion, respectively.
 * Inverted in Paranoia Agent, where the Theme Music belongs to Big Bad Lil' Slugger. If it starts playing, you're extremely screwed -- Slugger gets the powerup.
 * Macross, naturally, features a lot of this:
 * In one of two of the most iconic moments in the original series is the SDF-1's assault on the Zentrandi fleet, outnumbered somewhere around a hundred million to one. The music was basically all the previous songs put back to back. Then The Movie came around and presented "Do You Remember Love?" the track that is all but synonymous with the series and is the music for what is quite possibly one of the most awesome moments in Anime ever.
 * And don't forget about the final episode where Kamjin attacks Macross City... then the show's opening theme song starts to play as the Macross takes off one last time and blows the offender out of the sky with it's main cannon.
 * Macross Plus featured an interesting variation. The music that powers up is not the fast paced songs but.
 * Macross 7 puts this to the limit with The Power of Rock. Literally, listening to Basara's singing causes creatures to regenerate Spiritia, something the villains suck out and causes a person to go comatose. In the Grand Finale, his power up was so awesome that it overrode the Big Bad's effect of draining spiritia and helps recover all his teammates. It also featured a new song that played in no other part of the show, Try Again.
 * Not true. Try Again had been played at least twice beforehand, first when Basara blasted his song THROUGH A METEOR without damaging it to save Gamlin, and again when they tried (and failed) to defeat a Brainwashed and Crazy Gamlin.
 * Macross Zero inverted this. The Song of Ruin is not a good thing for people.
 * Macross Frontier does this a lot, especially episode 7. In episode 14,
 * Episode 4 featured "My Boyfriend is a Pilot" (from the original series) over Alto's "final exam" in his dual with Klan Klan. What happens next is an awesome fight sequence with choreography to the music.
 * In episode 24,.
 * The entirety of episode 25
 * Genesis of Aquarion has a Theme Music Power Up in nearly every episode (along with the usual subversion with stopping the song when the attack fails), and the last episode gets an awesome, gospel style version of the first theme song.
 * Umineko no Naku Koro Ni: For the protagonists "worldend_dominator", "Far", and "Dread of the Grave" are all indications that a Crowning Moment of Awesome will happen. For the antagonists it will be "happiness of a marionette", "mirage coordinator", "Golden Smile", or "Moon Rabbit's Dance".
 * "dreamenddischarger" takes this to another tier entirely. So does "the excecutioner", but only for the Big Bad.
 * Higurashi no Naku Koro Ni's games have it's own series of Songs, with various remixes of 'Dear You'. The instrumental version, 'Dear You - Destructive' is used during one of most Crowning Moments of Awesome, needless to say, Keiichi dodges bullets.
 * Princess Tutu. Admittedly, all combat is to ballet music, but you could always kind of tell who exactly was getting the power up.
 * Eyeshield 21 also has some examples of the "with lyrics" variety. The first appearance of "Be Survivor" comes to mind and, later "Chain of Power."
 * The Devil May Cry anime has a pretty cool theme song, which plays during the final episode when Dante activates his Devil Trigger to finish off the Big Bad. We don't see the full Devil Trigger and the fight is over in a few seconds, but the music makes the scene an odd combination of anticlimax and Crowning Moment of Awesome.
 * Burst Angel only has this happen in the last episode,
 * Shikabane Hime played the Opening Theme over Makina and Yamagami's first fight with Akasha to let them fight his horrible evilness.
 * Once YOU WA SHOCK/Ai Wo Torimodose's battle remix starts playing (or for that matter, the fight alteration of "Super Survivor" or "Tough Boy"), then there's no doubt Kenshiro will bring the ultimate form of pain on the bad guy of the day. Then, after the beat down, they are already dead.
 * One aversion however, is Jackal, a powerless dynamite-Spamming mook, who manages to live all through that music. And Ken was just fucking with him all that time anyway... up until Jackal calls upon Devil Rebirth.
 * Vision of Escaflowne does this sometimes. When the Dance of Curse starts playing expect some serious fighting.
 * One Piece has "Gomu Gomu no Bazooka!", which often plays when Luffy finishes off the villains.
 * Each character has their own. If a non-Strawhat has one, they're joining the crew.
 * If you hear the instrumental version of "We Are" (The show's first theme song), the whole crew is going to be breaking out the beatdown.
 * General Rule. If you are watching One Piece and Overtaken plays? Crowning Moment of Pure Awesome in the works. No Exceptions.
 * During the Impel Down Arc, Hannyabal attempted to invoke this by having soldiers play music at the beginning of his fight against Luffy. It didn't take.
 * And even the understandably silent written Manga made a spoof reference to this. When Ussop reinvented himself as Sogeking, he quickly made up and sung his own little theme tune, which was a joke at the time. Later, he turns up to save the day, and happily sings the theme tune to himself as he shoots at the crucial group of marines. Except the change of circumstances makes readers see the song in a whole new awesome light. It came back later when Ussop "transformed" to fight with Perona.
 * Outlaw Star - CRASH!
 * Basquash! doesn't show the usual title card or play the theme song at the start of episode seven, with the reason why being revealed at the end. It was being saved for Dan showing Rollingtown, for real this time, how Hot Blooded basketball is played. The theme song shows him the way.
 * Nearly any fight in The Third!, most notable One Woman Wail "Sword Dancer" during first and tension rising "Storm on the Battlefield" during last battle.
 * Most fights in The Law of Ueki start the opening theme as the final attack is used, which then continues through the whole opening, even if the fight has already ended.
 * Whenever Yuki Kajiura and the strings and chimes of Awesome strike up in Kara no Kyoukai, not only is the unkillable going to be killed, it's going to be spectacular.
 * In the Black Lagoon anime, various rock songs inevitably start up whenever awesomeness is about to come down. The most notable is the song "Peach Headz Addiction", which only plays when Revy lapses into Whitman Fever.
 * In the final episode of Ouran High School Host Club the ending theme starts early as and the episode had a special ending to avoid repeating.
 * Whenever Athena's Saints in Saint Seiya mustered their courage and burned their Cosmo beyond its limits, they'd receive either a full-on brass fanfare or a gorgeous orchestral arrangement of "Pegasus Fantasy". Asskicking of Olympian proportions would ensue.
 * In Gaiking, should you happen to be hearing the sound of trumpets - it means Daiya is about to kick ass.
 * Transformers Victory's opening theme music plays whenever Star Saber does something particularly awesome. Road Caesar and Landcross each have their own remixed version.
 * In Seto no Hanayome, San's "Song of Heroes" is a Theme Music Power Up, thanks to the Mermaid's Ancient Lyrics. Any time San starts singing it, Nagasumi is about to do something impossibly badass. And then there's the time that
 * Keroro Gunso example. In episode 103, just as
 * Revolutionary Girl Utena: The Movie. "Let's go, Utena. To the outside world." ~ Oooohhhh, yeeeaahhhh... ~
 * In Soul Eater Soul does this quite literally, as he is able to play a (technically imaginary) piano to co-ordinate him and Maka with their teammates.
 * Other than the Musical Assassin, there are usual examples in Kid's '...Have a nice dream' track, and Black Star's 'Never Lose Myself'.
 * Black Star also has Harmo NIZE.
 * Played straight in recent a recent chapter as Soul
 * In the Mazinkaiser OVAs, whenever Kouji lays the pain down his opponents, the song Mazinkaiser's Theme starts playing, though it's the short version. In the final episode, "Decisive Battle! Burning Hell Castle", the full version of it is played the moment Mazinkaiser unleashes Kaiser Blade and doesn't stop until he delivers the final blow onto Hell King Gorgon.
 * Shin Mazinger manages to pack three one after the other in the final episode, as the second opening, second ending, and finally first ending play in sequence over the final battle.
 * Tekkaman Blade: When Blade receives his Blastor power up, Eternally Loneliness starts playing. Blade proceeds to send Lance running with his tail between his legs, before blowing him up with a souped up Voltekka. The same Lance that spent the better part of episode bragging about how he was superior in every way.
 * 00 Gundam from Mobile Suit Gundam 00 initially failed to reach optimal operating conditions in light of an impending attack on the Gundam Meister's ship (Season 2, Episode 2). 00 Gundam gets its own semi-acoustic version of the soundtrack by the same name as Setsuna activates Trans-Am, thereby forcing the Gundam to reach a stable operating state. This results in all parties present pausing to admire the flash of emerald light and marvel at the Twin Drive system. The music starts up in earnest and 00 Gundam proceeds to rape the attacking "Ahead" mechs.
 * Also in season two, "Trans-Am Raiser", and the movie had "FINAL MISSION! QUANTUM BURST!" Whenever those two start playing, lots of stuff blows up at a constantly increasing rate.
 * Cowboy Bebop. In the final episode as, the next five minutes of awesome are shown with See You Space Cowboy, an arrangement of The Real Folk Blues, playing in the background. Crowning Music of Awesome with saxophone and piano!
 * In SD Gundam Force episode 52, the 3rd opening theme Taiyou Ni Kougarate plays when the heroes begin their ultimate attack on the Big Bad
 * Also, in just about every episode, the battle is resolved by the kid getting excited, which activates the Soul Drive, which starts the trumpet solo, which gives the Gundams the power they need to save the day.
 * The second anime of Fullmetal Alchemist has the fight against Sloth, where Olivier Armstrong is The exact same thing happens a few moments later when  Starts around 3:00 in this video.
 * Shaman King poses a subversion in
 * To Aru Majutsu no Index has "Jellyfish" by Mami Kawada. This plays when Index is alone and Sherry Cromwell's Golem attacks her.  until Touma comes along and cancels the whole summoning.
 * Also, Gensou Koroshi (Illusion Killer/Imagine Breaker) is Touma's trademark music for whenever he does something awesome.
 * In A Certain Scientific Railgun we have only my railgun, which plays when Misaka faces the AIM dispersion field beast (By giving a pep talk to the part of Saten's consciousness inside the beast). Kiyama-sensei even expressed awe at how much more powerful Misaka could be when fighting seriously. "This is...Level 5..."
 * Also at the end when they
 * The North Maiden of Star Driver always starts to sing before that episode's giant robot battle.
 * With her being put on a boat resident Genki Girl Mizuno seems to have taken over for her.
 * And now with Mizuno leaving, TMPU has fallen to the east maiden
 * In The World God Only Knows, the opening theme plays when Keima goes into God of Conquest mode in episode 12 of Season 1.
 * The final battle (against The Rival Papillion) in Busou Renkin is accompanied by the title theme. It is, like their first fight, fast paced and impressively choreographed, even if it is more down to earth than the fights involving gravity manipulation and Humongous Mecha.
 * When Shin Getter Robo uses Stoner Sunshine against Shin Dragon, a Badass Theme Music Power Up starts up raising the level of epicness in the scene.
 * When they made Super Robot Wars Original Generation into an anime, this was guaranteed to be in effect. The most notable occurrence is in the second series The Inspector when Latooni and Schine debut their Fairlions to the tune of a vocal version of Dancing Faeries, their shared theme.
 * In Nerima Daikon Brothers, the titular band often sings a revised version of their theme song with lyrics adjust for the villain whose butt they're about to kick. It's basically a show rule that if the theme song's not playing, they're not about to win.
 * The Meaning Of Truth, the theme of the F-Zero anime, starts up during that famous scene at the end, where
 * Black Butler has a discordant version of "London Bridges Falling Down" play during Sebastian's final battle with  at the end of the first season. Seriously. And in context it was awesome.
 * Panty and Stocking With Garterbelt plays Fly Away (Now) during pretty much any scene which tops the awesomeness of the previous scene in which Fly Away (Now) was played.
 * It is fairly common before Ep. 5, but afterward becomes less and less common until the Battle Royale With Cheese at which point you will cheer and applaud when it plays.
 * Zoids: New Century Zero- Strike Lazer Claw!
 * Happened a few times in Sonic X. Exactly which theme music it was varied.
 * In Street Fighter II: The Animated Movie, Ryu and Ken's Final Battle against M.Bison is set to "Itoshisa To Setsunasa To Kokoro Tsuyosa To." This was, in a way, foreshadowed by the encounter between Chun Li and Vega, where an instrumental version of said theme shifts the horrible beatdown to the heroine's favor.
 * Persona 4: The Animation. It is the dead of night. All hope seems lost. Yu is alone, beaten but not defeated. All his efforts have been in vain, and it seems nothing he can do will help him overcome. But then he stands, determination burning in his heart. He rallies his strength and summons the original game's battle Theme Tune, "Reach Out To The Truth," and he faces out, he holds out, he.
 * In Rental Magica, when Itsuki removes his eye-patch, the music starts, and he says a variant of, "This is an order from the President!" asskicking will commence..
 * When Fairy Tail's Dragon Slayer theme starts playing, expect much ass kicking and property damage to ensue. This theme tends to be reserved for the seriously close fights; for more standard epic beatdowns, they use Natsu's main fighting theme.
 * Rurouni Kenshin has an unusual example of this trope. Kenshin's personal kick-ass music is an acoustic guitar theme that plays whenever he does something Badass. Which is fitting considering the character.
 * Irresponsible Captain Tylor likes to play with this. Whenever Straight Man Lieutenant Yamamoto tries to do something awesome and profound, his theme-tune starts up - a militaristic, Music to Invade Poland To-ish piece that brings to mind Toshiro Mifune's samurai-era masterpieces. Only for it to, inevitably, be interuptet by Tylor's easygoing comedy-movie-style theme when Tylor interrupts his badassery with something utterly stupid that nonetheless somehow manages to save the day. He even manages to throw down the occasional Record Needle Scratch, usually followed by a few seconds of complete silence while everybody in the area stares at him in gobsmacked disbelief.
 * In Puella Magi Madoka Magica, Mami has a pretty awesome one when transforming into her magical girl outfit.
 * Gun Buster plays it straight when the Buster Machine rises from Exelion while the Gunbuster March plays. And then, in Diebuster.

Films
""Let's roll!""
 * Subverted twice in a very short time in the Lord of the Rings film Return of the King. After the Riders of Rohan and Gondor coalition forces have routed the orc forces, and the king has shouted "Make safe the city!", the triumphant music abruptly fades away as the audience hears what sounds like a distant rumble of thunder, and swiftly turns includes the bellows of the towering Mumakil war-elephants-on-steroids and the warchants of their riders, the Maori-reminiscent Haradim.
 * However, the music returns as a counter charge is ordered, and the cavalry make yet another music-backed charge to the line of Mumakil...only for the music to be cut off as if someone pulled the plug from the sound system, or if the orchestra themselves had fled the battlefield upon realizing what a terrible idea charging fifty foot elephants with horses was. Incidentally, the music is cut off at the exact moment that one of the warbeasts swings its tusks, sending a horseman screaming into the air, then smashing more aside with its feet. It takes another few minutes (film-time) before anything resembling victory seems possible...and then the Nazgul, including the Witch-King, show up.
 * Played straight a little earlier; when Aragorn grasps hold of Andúril for the first time, his personal theme music swiftly switches from a bouncy Fellowship-based ditty to a roaring orchestral King of Gondor crescendo.
 * King Theoden gets one when he declares that Rohan will fight alongside Gondor.
 * The main theme of Once Upon a Time In China plays whenever Jet Li's heroic lead, Wong Fei Hong, takes on the forces of evil in said-movie-series.
 * It's traditional to use that for Wong Fei Hung's theme song in any movie about him. Example: Jackie Chan's Drunken Master plays it when Fei Hung is winning his fight against the Big Bad.
 * The Bride from Quentin Tarantino's Kill Bill.
 * Indiana Jones has his distinctive theme play whenever he does something Especially Awesome.
 * Said theme was so awesome that Turkish Star Wars shamelessly stole it and used it for Every. Single. Freakin'. Fight scene.
 * James Bond is in the rare and enviable position of having two Theme Music Power Ups -- the "James Bond Theme", and the music from the opening titles of each movie. See the pre-credits sequence from Tomorrow Never Dies for a particularly badass example. On the other hand, if the opening song is a Villain Song, Bond had better watch out when it starts playing on the soundtrack. Example: Goldfinger's aerial raid on Fort Knox, set to a thunderous version of his The Villain Sucks Song.
 * Two examples that simply must be mentioned:
 * Bond re-entering the scene in a tank by taking the shortest route through a concrete wall in Goldeneye.
 * "The name's Bond... James Bond."
 * And then there's Bond's other theme song, the 007 Theme from the From Russia With Love soundtrack. Pretty much any time this music comes on, you know something's about to be beaten up or blown up. It was used to particularly great effect in the "Little Nellie" sequence in You Only Live Twice, as well as the air assault on Blofeld's rig in Diamonds Are Forever.
 * In the Spider-Man films, Spidey's action scenes are usually accompanied by his distinctive Leitmotif. The villains also get their own theme music. In climax of the third one, Spider-Man's theme gets very noticeably cut off whenever the villains get the upper hand.
 * "Holding Out for a Hero" in Short Circuit 2; for those too young to remember that one, it was also in Shrek 2. With full orchestra support from Harry Gregson-Williams in the latter case.
 * At the end of the Mission Impossible movie.
 * Even better in the second one, when
 * Right towards the end of the 'The Matrix'', when Neo becomes The One, and is seeing the "code" for the first time. One-handed kickassery follows.
 * Most people will never be able to hear The Propellerheads' "Spybreak!" without thinking of the lobby shootout scene again.
 * The Rocky movies are no doubt well-known for their sudden comebacks, almost always accompanied by one of Rocky's many theme tunes. Usually, just as the finishing blows are made, the music builds to a dramatic climax. This is no more evident than in the fifth movie (otherwise not worth the time) where, as Rocky lies concussed in the streets during a brawl with Tommy Gunn, he goes into an almighty hallucination, remembering his dead trainer Mickey before finally snapping out of it as Mickey screams at him "Get up, you son if a bitch... 'cause Mickey loves ya." The music swells as Rocky rises again... then it suddenly bursts into a weird ghetto remix.
 * Parodied in Kung Pow: Enter the Fist, where Master Betty occasionally shouts, "Play my kick-ass music!" One of his minions then plays "Baby Got Back", to which tune Betty pummels his victim.
 * "By the way, you must beware of Betty's iron claw. They are sharp, and they hurt. And beware his song about big butts, he beats people up while he plays it!"
 * And in the final showdown, the Chosen One throws a shuriken at the boom-box, causing it to start playing the Ram Jam version of (probably) Huddie "Lead Belly" Ledbetter's "Black Betty".
 * Sometimes done just before a scene's climax, when the heroes have the upper hand and the enemy hasn't made his final play yet -- such as in the Scooby Doo movie, where a remix of the classic theme plays for a while before the gang really winds up in trouble.
 * "Secret Agent Man" playing in the final battle of the first Austin Powers movie may qualify; again, it dies down before Austin's final confrontation with Doctor Evil.
 * Backs up the Guarani a couple times in The Mission. Sadly, it is not quite enough.
 * The first twenty seconds of the track "Beelzeboss" from Tenacious D in the Pick of Destiny act as a Theme Music Power Up for the Devil.
 * At the end of Pirates of the Caribbean: Dead Man's Chest, Jack Sparrow's confrontation against the kraken is made even more awesome by the remix of He's A Pirate that plays during it.
 * And then abruptly turns tragic as the heroic strings drop into a dying fall... just as the Black Pearl is pulled beneath the waves.
 * Probably averted in the first Pirates of the Caribbean film. Jack Sparrow's first scene in the film is standing on the mast of his sinking ship, and yet the music that scores this scene is unabashedly heroic (and serious to the point of self-parody).
 * Unaverted in Pirates of the Caribbean:At World's End, when Jack Sparrow comes over the sand dunes in Davy Jones' Locker in a reference to his first entrance.
 * The sinking of the Endeavour
 * Excalibur, which popularized "O Fortuna".
 * Star Wars has a general rule: if the "Force Theme" is playing, it's because the characters are doing something epic. If the title theme plays, it's because they're being just plain badass.
 * 'Film/'Return of the Jedi'' gives Luke a big Theme Music Power Up in the Sarlacc pit scene.
 * The Emperor gets one as well when his rather creepy theme plays as he electrocutes Luke with Force lightning. Has elements of The Day the Music Lied, though, since that's when
 * Also, of course, there is a general rule in all Star Wars films that if you can hear Imperial March, it means The Dragon is being awesome again.
 * Even detractors of the Star Wars prequels admit that one of the coolest moments in the series was near the climax of The Phantom Menace when just as the heroes are ready to flee the scene, a door opens, a cloaked figure appears (Darth Maul), and the first few notes of the "Duel of the Fates" theme are heard.
 * In the original film, the power up music comes at an interesting moment: when Luke shuts off his targeting device the score shifts from tense to triumphant. It means he's decided to trust the Force and is on the path to becoming a Jedi. Actually blowing up the Death Star is just a detail.
 * Mr. Mistoffelees on the filmed version of Cats. His song, though enjoyable, is so odd and repetitive and full of praise that it seems he's doing the song mostly to get the crowd to believe in his powers so he can actually do anything.
 * However, since the song is actually performed by Rum Tum Tugger, it could be argued that Tugger is actually trying to convince Mistoffelees that he can do the magic that needs to be done.
 * When it's time for a dogfight, what's the first thing the hero does in Iron Eagle? Put some rock into his tape deck, of course.
 * Why the Superman wasn't added a long time ago is beyond me. It is the sound of powering up.
 * Later used/homaged in a climactic moment of I'm A Marvel... And I'm a DC's "After Hours" storyline. The circumstances did it justice. Which is to say, it was appropriately awesome.
 * In Godzilla Final Wars, Godzilla's new theme "King of the Monsters" kicks in just as he blasts off one of Keizer Ghidorah's heads after being revived by Ozaki in the Gotengo. Godzilla then proceeds to utterly destroy Ghidorah by tossing him into the air and blasting him with a spiral beam.
 * A possible subversion or inversion could be the laughably quick death that the American Zilla receives from the true Godzilla while the English (but not American) song "We're All to Blame" plays over its fight.
 * In Galaxy Quest, at the end of the movie, the real Protector, with the cast members on it, crash-lands at a Galaxy Quest convention. The film's Big Bad, Serris, is still alive -- until he's shot, in full view of the entire convention audience, by "Commander Peter Quincy Taggart". The film's triumphant theme music plays. It's over. However, in the beginning of the movie, the guy was a pure egotist, basking in the spotlight at appearances and so on. Now, he's learned his lesson, and he invites the crew up to take a bow. When this happens, the music switches to a higher, remixed triumphant version with plenty of choir -- the Commander's won the real battle. The movie ends there.
 * Iron Man had great fun with this, playing the driving guitars of the hero's theme and then stopping the music abruptly when circumstances changed. Best example would be
 * And the literal powering up scene. Stark has decided enough is Enough and decides to go to settle the situation in Gulmira, personally. As Stark stands in the middle of his workshop the floor opens up and numerous robot arms apply his Mark III armor, now with iconic red and gold scheme. The track that plays is appropriately titled "Iron Man", on the soundtrack by Ramin Djawadi.
 * Similar moment, although with a different soundtrack, in Iron Man 2, accompanying the racetrack fight.
 * "Yor's world, he's the man!"
 * Two moments from Star Trek First Contact spring to mind: the battle against the Borg cube at the start of the movie, where the Enterprise swoops to the rescue to the sound of an absolutely epic fanfare, and the fight on the deflector dish, where each time the Borg gain the upper hand, a more thunderous version of their Leitmotif plays.
 * In The Wrath of Khan, we get three power-ups: Once when the Enterprise leaves its dock, one for Khan during his surprise attack, and again for the Enterprise during the Lock and Load Montage.
 * Pretty blatant in the climactic fight scene of Only the Strong, a 90's action film about capoeira (a Brazilian martial art):
 * Whenever Optimus Prime enters the big ending battle in both movies, the music soars as Prime either epically transforms or  Both complete with a one-liner to emphasize that yes, this is awesome.


 * Just before the 'two against five' sequence in The Good the Bad And The Ugly, a burst of the theme music plays as Blondie asks Tuco "Were you going to die alone?" and joins him to fight Angel-Eyes' men.
 * Happens subtly in Star Trek. If you hear a snippet of the main riff from "Enterprising Young Men", ass-kicking will soon ensue. Especially egregious when Sulu gets dangerous.
 * In Halloween (2007), Michael gets better from his sister stabbing him through the shoulder and recovers his discarded mask when his "stalking" theme starts up.
 * In Beverly Hills Ninja, there is a fight with the obligatory Kung Fu Fighting by Carl Douglas. When the fight gets more intense, it hilariously speeds up.
 * The Man Who Saves the World is really shameless about this. Every single time the hero starts winning a fight, his music starts playing. The real kicker is that his music is just the Indiana Jones theme.
 * Once Upon a Time In The West Sergio Leone is pretty good at this, especially in OUATITW, where Charles Bronson has one of the best themes ever associated with a movie protagonist. The spooky sound of the hamonica accompanies his raging revenge through the movie, and every time you hear it you know that he'll do something awesome.
 * When watching the original 1989 Batman, the minute you hear any version of Danny Elfman's classic Batman theme, there's gonna be some kicked ass. No questions asked.
 * This applies to Batman Returns as well.
 * This also happens in the Nolan films. Zimmer's Batman anthem is maybe less memorable than Elfman's, but it's always there when Batman kicks serious ass (listen to the score in the "Swarm of Bats" scene from Batman Begins).
 * Conan the Barbarian (1982) by Basil Poledouris
 * Robocop (1987) by Basil Poledouris
 * If the song "We Are Sex Bob-Omb" can be seen as Scott Pilgrim vs. the World's theme, he definitely gets a power up from it before the final fight. Twice.
 * In Gladiator, General Maximus has a driving, forceful orchestral battle theme only heard twice, once on the German battlefield and once in the Colosseum. In both moments he is leading armies to victory like a true frontline general.
 * The music in Thor kicks into high gear when the eponymous hero proceeds to kick major ass.
 * Blatant in Jimmy Neutron: The Movie - whenever he starts implementing a new plan, or is in the middle of using ANY invention for WHATEVER reason, a variation on his theme tune starts playing. Yes, even when he's just getting ready for school. Either that, or some new-wave, boppy, pop song comes on (as evidenced during the defeat of the Yolkians in the arena).
 * The ending of the original Dawn of the Dead. The main guy is trapped in a room with a hoard of zombies about to come in. He gets ready to kill himself, but he suddenly turns the gun around and shoots a zombie instead. Cue the cheesiest patriotic fanfare you can think of as he pushes zombies out of his way and runs to escape with the main girl. It's a good thing that music came out of nowhere and made the zombies completely ineffectual, or it would have really been a Downer Ending, which is actually what the original script called for.
 * Kick Ass, Hit-Girl and Bad Reputation; exactly as it says in the title ensues.
 * Invoked in The Avengers: When Iron Man arrives on the scene, he hacks the nearest speaker system (which happens to be Black Widow's jet) to play ACDC.

Literature

 * An affectionate parody: Acheron, the Atlantean god-turned-vampire warrior of Sherilyn Kenyon's Dark-Hunters series, has "Sweet Home Alabama" for his theme music.
 * Artemis Fowl sometimes has Plotting Music in his head when he's coming up with his plans. It's generally classical, like Beethoven's Symphony No. 7.

Live Action TV
"Jasmine: Please excuse me. (place hand on Ryouga's hand)
 * Xena: Warrior Princess, as sung by the Bulgarian Women's Choir.
 * Numerous examples in Power Rangers in all of its incarnations. For example, after Tommy lost his Green Ranger powers in the first season, yet proceeded to fight off Goldar anyway (to the tune of "Go Green Ranger Go").
 * Theme Music Power Up is the only context where we get to hear the original Power Ranger theme with lyrics in its verses. ("No one will ever take them down / The power lies on their si~i~i~i~i~ide! / Go, go, Power Rangers...") Giving a previously instrumental theme some lyrics, when done right, seems to give a power-up to the theme music.
 * Particularly, in the crossover episodes, the visiting team gets the theme music for the previous season when they escalate. In Operation Overdrive's Once a Ranger, we're treated to five earlier incarnations of the theme music, cleverly mixing together (Well, four; for some presumably legal reason, Adam gets a new theme song rather than the original "Go, Go Power Rangers" theme.).
 * A notable non team up example happens in Lost Galaxy right after the Rangers receive the Lights of Orion.
 * Some Power Rangers series have also inverted this trope, giving Mooks like the Cogs and Tenga theme music when they fight the Rangers. They almost always lose.
 * This happened in Sentai too, dating all the way back to Goranger, with "Akuma no Kurojuujigun" being the theme of the Kurojuujigun.
 * At times in Power Rangers Wild Force, if there were no music during a ranger fight, you know they're going to get whupped.
 * Happens in Super Sentai too... although Chikyuu Sentai Fiveman took it too far.
 * Kagaku Sentai Dynaman had this to the extreme, with an opening theme made to sync to the Finishing Move, the Super Dynamite.
 * Tokusou Sentai Dekaranger vs. Abaranger ended up Lampshading the whole thing:

Narrator: (while clipshow of Abaranger goes on) Jasmine is an ESPer. Whoever she touches, Jasmine recaps his memories.

Jasmine: Seems true for now. I have my doubts for them though -- (walks to the camera) -- Aba-Aba-Aba-Aba-Abaranger!

Umeko: What the heck was that?

Jasmine: Don't know either. It was on loop in his brain."

""This intro makes me feel like I am about to witness the most important event in the universe." -sterpinator, YouTube commenter"
 * Happens in the opening fight scene in Samurai Sentai Shinkenger, and on the same footage in episode 19 (which is actually the Origins Episode) of Power Rangers Samurai.
 * Kaizoku Sentai Gokaiger takes this concept and runs with it. As an anniversary series for the franchise, the Gokaigers not only get a Theme Music Power Up from their own theme, but the theme music of whatever past sentai team is getting spotlighted that episode.
 * The A-Team theme tune, during each episode's A Team Montage.
 * Has been lovingly taken up by Top Gear, who have used it repeatedly when doing something particularly A-Team-y to their vehicles. Has gotten to the point that Clarkson sequed into an A Team Montage by saying, "And then it was time to cue the music ..."
 * Kamen Rider Den-O has a different version of "Double-Action" for each of Ryotaro's five forms. Ryuutaros, however, takes it a step further. He gets a hip-hop remix of the show's Theme Song and the above mentioned "Double-Action", that play almost every time he shows up. This includes when he's stalking rival Sakurai Yuuto. Speaking of, Yuuto and his partner Deneb get their own theme music, called Action-ZERO.
 * All Toku use this trope to one degree or another. Grand Finales usually involve the "series Theme Song" variant, while the debut of Sixth Rangers usually gives them a specialized theme. This may be to sell the soundtracks.
 * Though it doesn't quite fit under a category, when one of the Riders in Kamen Rider SPIRITS is about to have a nice big one-against-all-of-his-monsters-of-the-week-ever battles, the lyrics to an appropriate theme song are written out on the page (V3's sequence is notably impressive).
 * Especially powerful in Kamen Rider BLACK's final episode when
 * "W-B-X ~W-Boiled Extreme~", the theme song for Kamen Rider Double, plays exactly three times during the series: during the fight where the Riders finally get the upper hand on the Weather Dopant, in the penultimate episode when, and at the end of the final episode when . It also gets played in The Movie during the final battle with Kamen Rider Eternal,
 * Doctor Who never uses the main title theme itself in the scores to the episodes. However, in the new era:
 * The Doctor had "The Doctor's Theme" in Seasons 1 and 2 supplemented by "All the Strange, Strange Creatures" in Season 3 as his theme, with the latter playing whenever it was time for action. The Doctor's Theme comes back all powered up for season 4, with an instrumental in "Forest of the Dead" and orchestration in "The Stolen Earth. Then, in the finale of the Tenth Doctor (and of Russell T Davies as showrunner), the two themes were combined to score the Doctor flying to the mansion and dropping down onto the Master. And finally, to overscore the Doctor's regeneration, they power it up one last time.
 * The Daleks' Hebrew choral theme becomes twice as powerful in "The Dark and Endless Dalek Night," and an echo of it is heard in the introduction of the New Dalek Paradigm.
 * Rose's theme is powered up when she is superpowered by the Tardis.
 * Martha's theme becomes "Martha Triumphant."
 * Donna's bouncy theme becomes more complex when she reunites with the Doctor.
 * And now the Eleventh Doctor's theme becomes louder and stronger for special occasions.
 * Airwolf, a lot, including literal cases, where the theme tune plays as Airwolf starts up, and goes full-blast during the climactic fight scenes. In fact, you can usually predict down to the second when the final explosion will take place as it will be in time with the climax of the theme.
 * On Heroes a ticking clock sound starts playing whenever Sylar gets up to his serial killer shenanigans. It fits his backstory as a watch repairman, and is damn creepy to boot.
 * In the Season 3 episode "I am Become Death", this trope is played around with when Sylar's theme is played again for another character, It's creepy and effective.
 * Batman usually fought goons to the sound of his theme music. And it was AWESOME.
 * Doubly awesome as every BIFF and POW is accented by a musical sting.
 * Spaced spoofs by powering with another show's theme: Mike gets brooding Mad Artist Brian to go from mouse to man by playing the Thunderbirds theme.
 * Another episode uses a drum and bass remix of the Imperial March over a Mission Briefing scene as Tim tries to power up the rest of the gang.
 * "Where's Mike?" "He's over there!" Dancing to a dance remix of the A-Team theme (youtube link was Screwed By the Lawyers).
 * Buffy the Vampire Slayer did this in its first-season finale "Prophecy Girl," playing the show's theme (performed by Nerf Herder) during the climactic fight - the only use of that arrangement of the theme music within an episode.
 * In an example of the character playing their own theme song, basically any time Omar Little of The Wire whistles "The Farmer in the Dell," odds are he's about to add yet another act of pure badassery to his resume.
 * Everytime Grover transforms into Super Grover in Sesame Street (He gets a version with Rock Guitar in Elmo Loves You)
 * Happens in the very first episode of Star Trek the Next Generation, when the crew successfully pull off the first saucer separation while at Warp 9.5.
 * Oddly enough, even a network can be powered up through theme music. Remember "HBO in Space", the ident to new movies HBO used in the 80s and 90s?


 * This happens twice in a single episode of the reimagined Battlestar Galactica. In Exodus Part 2,
 * The pilot episode of Firefly features dueling theme music during the aerial chase between Serenity and the Reaver ship, with the Reaver's theme growing louder and more ominous the closer they get - only to be blown away by Serenity's theme when the ship pulls its Crazy Ivan maneuver and leaves them in the dust.
 * Smallville brings the series to life for a last time, delivering
 * The Incredible Hulk: Tense music when Dr. Banner is Hulking Out, and then when Hulk kicks ass.

Newspaper Comics

 * Popeye's use of this trops was parodied in Pearls Before Swine where the croc forgets to chew the spinach before swallowing, and chokes to death. ("Tooday's lesson: Always chew you food.")

Video Games
The second example is in the extended ending. If you fight the normal final boss, Graham, a certain way, you will  This allows you access to a previously sealed area of the castle...  The battle is a tough one, too -- especially because   has the best theme music in the game. "Reid: We will not LOSE!!"
 * Phoenix Wright Ace Attorney uses this trope to extremes unplumbed by man, playing it straight and subverting it at will as the case swings back and forth in and out of Phoenix's favor. A Double Subversion occurs in the first game's third case: Phoenix is out of ammo, the witness/killer is about to get off the stand... and then the song "Investigation ~ Cornered (Variation)" (very dramatic and heroic music) starts up as Edgeworth objects to keep the witness on the stand. The music dies as Edgeworth realizes he doesn't have a question, the judge is about to let the witness go... and then the music starts up again as Edgeworth has a burst of inspiration.
 * Note that in the second trial, when  the music starts up for Edgeworth as he proceeds to help weave a false testimony, triggering part two of the confrontation. The music starts up again when Wright has   cornered for the second time, and Edgeworth attempts to obscure the truth once again by extending the trial.
 * The second game uses this in an interesting way:
 * This happens again in Trials and Tribulations when
 * In fact, the use of this trope verges on being a gameplay element - whenever you present the correct evidence at a contradiction, the cross-examination theme will always stop as Phoenix objects, in preparation for the heroic music to start up once he points out the contradiction. If you're wrong, the music will just keep going as he takes a penalty. Save right before every objection you're not sure of, and wait for the music cue with your finger on the power switch in case you were wrong...
 * And in the second to last piece of evidence of the third game (the one with the first game's "Cornered" theme) the music always stops and Godot's next line is the same if you present the right piece of evidence or not.
 * In the fourth game, the prosecutor was a guitarist for a band and his theme music turned out to be one of his actual songs. Further, he will perform awesome air guitar in court, which does everything from double your penalty bar to break down a witness.
 * In a bit of fridge logic, the theme will play in a flash back to before the song was written.
 * Don't forget Godot. He has his own smooth jazz Leitmotif as his CELL PHONE RINGTONE.
 * Appropriately, this carries over to Phoenix Wright's appearance in Ultimate Marvel vs. Capcom 3. While his normal theme song is the first game's "Objection!", whenever he gathers enough evidence to go into Turnabout Mode, this (as well as any other theme that is playing) will be replaced by the iconic "Cornered" theme.
 * Remember Edgeworth's awesome theme song from Ace Attorney 2? The one that became the Big Damn Heroes theme song for the next two games? It's received a remix on his own game, Investigations, to be his Objection! theme. And on the second one, it's basically the ground stone for every theme envolving him.
 * In the Gamecube version of Soul Calibur 2, Link's theme starts blaring as he begins his destined battle against Raphael. Hearing the tune really pumps you up to kick Raph's arse.
 * The Battle of Ostagar.
 * All of the companion missions in Mass Effect 2 use that companion's theme music, which steadily gets more awesome over the course of the mission.
 * This plays during the sequence on Rannoch where.
 * Super Metroid's Final Battle, where the remixed Crateria theme starts thundering over Samus' "My Name Is Inigo Montoya" moment against Mother Brain.
 * Samus does have her own theme music by this point in the series, which plays over her revival (both times) in Metroid Prime 3: Corruption and over Super Metroid's opening text crawl and end credits. It also gets an orchestral remix in Super Smash Bros Brawl.
 * That Brawl remix itself becomes a Theme Music Power Up during Subspace Emissary. It plays when Samus gets her Power Suit back on the Floating Continent.
 * Speaking of Metroid... Late in Metroid Zero Mission, Samus is stripped of her armor, and is forced to retreat from a pack of murderous space pirates who can kill her in one shot. She gets two consecutive Theme Music Power Up moments:
 * After gaining a new, more powerful version of her armor in the Chozo Ruins, Samus gets the "got item" theme, but instead of the version found in the 8-bit NES Metroid, it sounds more like the Metroid Prime-and-later versions. Sends chills up and down the spine.
 * Samus then retaliates against the pirates with a vengeance, now able to destroy them in one shot, with an up tempo version of the Brinstar theme song blaring all the while.
 * The final boss of Metroid Prime is accompanied by the already slightly creepy, Ominous Latin Chanting filled main menu music, warped to sound even stranger and more alien. Given that the main menu has the interior of a metroid for its backdrop, this really drives home just how wrong the final boss is, even compared to life energy sucking floating fanged jellyfish.
 * Both Ridley and Dark Samus have Evil Theme Music Power Ups in Metroid Prime 3: Corruption. In the case of Dark Samus, it's a Big Damn Villain moment too.
 * Metal Gear Solid 3 invokes the song Snake Eater if the player is running out of time in the final battle.
 * Metal Gear Solid 4 plays with this, where playing certain songs on the I Pod provides ingame bonuses. Naturally the ridiculously awesome Metal Gear Solid 3 theme (Someday, you walk through the raaaaaaain, some day you'll feed on a treeeee frog!) makes you almost unstoppable.
 * Then there's the finale of MGS4, where
 * Mega Man series examples:
 * Zero in the Mega Man X games has a different theme song in every game, and it always plays when he does something awesome (blowing off Vile's mech's arm in the first game, sacrificing himself, destroying a copy of himself in just three shots, etc.).
 * This holds true in the Mega Man Zero saga. Whenever that particular game's Zero theme song starts sounding, rest assured -- you're about to do something very cool.
 * Also, the music changes into the foreboding final stage theme after the first form of the final boss is defeated and Then Zero has his World of Cardboard Speech and the absolutely awesome final boss music starts up.
 * And Mega Man Battle Network games have a theme in each game, based around the same two tunes throughout the series, which is played for no other reason other than to show off how something heroic is going on.
 * The tracks are actually called "Heroism".
 * Not to mention "You're Not Alone" for the Big Damn Heroes moments.
 * In what can only be described as Mood Whiplash, the 6th game has a slow, sad version of the theme, as to get rid of the Cybeast inside the titular character, then "You're Not Alone" plays as the event actually happens.
 * The Mega Man NT Warrior anime even did this in the Japanese version -- if you heard the theme song, it was time for the heroes to start winning. Without fail. The dub did not retain this tradition.
 * The final match of the N-1 Grand Prix was, of course, between Netto and Rockman and Enzan and Blues. The fight takes place while the Anime Theme Song, "Kaze wo Tsukinukete", blares in the background, and both Navis pull off the Program Advance Beta Sword and commence a swordfight so epic the holographic display almost can't contain it. And then Blues wins by way of Single Stroke Battle. Rock falls over, and Blues and Netto both congratulate Rock on his hard fight while a slow, sad ballad version of the very same opening theme plays.
 * In Mega Man ZX, you get a brief moment of your protagonist's bright idealism, accompanied by Green Grass Gradation (the very upbeat and optimistic Area A music from the very beginning of the game), before commencing the final battle.
 * What, nobody thought that Mega Man Legends was worth mentioning? Juno has J.S. Bach's Fugue in G Minor; unattractive name, epic pipe organ. You can listen to it here, or if you want to see how well the music suits Juno, watch the battle here. The music gets even more epic when you enter into the second part of the battle; click here to see what I mean.
 * During the second fight with Dracula in Super Castlevania 4, the music changes from the level music to Simon Belmont's theme. Note that this has worked in reverse as well; Dracula's theme music, Dance of Illusions, usually plays in the fights where he's the most difficult to defeat (like in Dracula XX, where the battle takes place over a series of bottomless pits).
 * Two examples of this one in Castlevania: Aria of Sorrow. In the first example, when you enter the boss room for The Arena, the normal boss music plays, as a cloud of bats flies outward and reforms into one Giant Bat. Then, a giant hand stretches out from the background (a huge shattered cage) and crushes the bat in its grip, just as the music changes to an entirely new boss theme. You end up fighting Balore (a giant ogre), one of the tougher bosses in the game.
 * This is essentially the effect of Star Power in the Guitar Hero games. Once activated, every note you successfully hit earns you double points, and the crowd rhythmically claps in unison. This is a great way to save you from certain death on difficult songs like "Bark at the Moon" and the faster second half of "Hangar 18".
 * Used throughout the Halo series. The Halo Theme generally starts playing whenever things get particularly exciting -- a narrow, timed escape, a huge, 3-way battle, etc. And, of course, whenever Master Chief does something utterly awesome, the theme WILL be playing.
 * Depending on how awesome whatever Master Chief is doing is, you might get the "Brothers in Arms" mix, the "Rock Anthem / Mjolnir Mix," or the "Covenant Dance" mix.
 * The best example being the final mission of Halo 3, which consists of one of the most epic escape sequences in video game history.
 * The Arbiter actually gets a mix of his own as well: "Unyielding," introduced in Halo 2, which plays when riding into battle against the Brutes in the last few levels. This track is later spliced into the Halo 3 version ("One Final Effort") that plays during the big escape at the end.
 * How has the "Breaking Benjamin Room" of Halo 2's Gravemind mission not been mentioned? Towards the end of the level, the player must go through a room full of combatants from both the Elite and Brute factions in a firefight. Breaking Benjamin's "Blow Me Away" plays through here, and the rock quite fits the awesome battle the player is about to participate in.
 * In Halo 3 ODST, expect varients of the Menagerie or Orbital Drop Shock Trooper to kick in whenever something awesome happens. And of course, Halo Reach continues the tradition with variants of Unreconcialed, Lone Wolf, or Noble Mission kicking in whenever Noble Team readies up for asskicking.
 * Each area in Phantasy Star Online has two songs (or parts if you see the song listing in the Sound Test or the OST). Part one is soft and calm while part two, which starts up when enemies attack, is more intense and has a harder beat to it. Both parts last almost the same length and have the same BPM, which lets the BG music flow from one song to another as if it were just the same song just getting more intenser. The intensity between the parts goes up with each episode as well.
 * Sonic the Hedgehog has been doing this lately. When someone goes Super at the end of each game, it is always accompanied with a Theme Music Power Up.
 * Sonic the Hedgehog 2 did it best with the Super Sonic theme - music that tells you immediately that all bets are off.
 * With the Adventure series giving each playable character theme song, said theme tunes were often used as leitmotifs, which ended up having this effect at times. Take, for example, Sonic Adventure 2. Dr Eggman's Egg Golem. In the Dark Story, Eggman moves to strike Sonic, to his own theme music. Then Sonic's theme tune suddenly takes over. Sonic dodges the attack, jumps on the Golem's head, and - with a TERIAAAAA! - delivers a single flying kick to the mind-control device on the Golem's back, which destroys it and sends it attacking Eggman instead.
 * Inverted in Final Fantasy VII: A Flash Back to the Big Bad's deteriorating mental state is accompanied by a few, looping malevolent chords. When he snaps, they extend and turn out to be the opening of his Leitmotif.
 * Not to mention the full-on Ominous Latin Chanting excellence of the final boss fight.
 * "One Winged Angel" is used several times through the VII Compilation as a Theme Music Power Up, most notably the above-listed transformation into Safer Sephiroth, as well as the fact that the song pretty much brought Sephiroth back from the dead.
 * In Crisis Core, there's a cutscene showing Sephiroth, Genesis and Angeal having some fun on top of a virtual version of the Junon Cannon. When Genesis gets a little too serious about the fight, a version of "One Winged Angel" kicks in to show that Sephiroth is no longer playing around.
 * Locke's theme is the standard Theme Music Power Up in Final Fantasy VI
 * When the main plot of Chrono Trigger starts up, they even let you bask in the theme music during enemy encounters.
 * Also, characters' personal themes. Frog is particularly notable for this.
 * Magus has a theme song that's awesome enough when your party is fighting him. However, if you happen to have him in your party when fighting the Bonus Boss,, he personally taunts his enemy and replaces the normal boss song with his own.
 * When Dalton commandeers the, he complains about the heroic music (which is in fact the main protagonist's theme) that starts as it engages ("No, no, no, no...! Stop the music!") and replaces it with a more villainous tune. ("Ha! There we go!")
 * Gig, Omnicidal Heroic Sociopath of Soul Nomad and The World Eaters, has three theme songs. Consequently, he has three different stages of Theme Music Power Up depending on which one's used, ranging from "you'll receive a verbal smackdown" to "you're Deader Than Dead, and so's your Throwaway Country And Your Little Dog Too".
 * In the Advance Wars 2/DS/Days of Ruin, when a CO Power is used, the normal CO theme will be replaced by a heavy metal tune depending on the CO's faction.
 * Some of the effects last until the next day/turn however, even though the theme is replaced by your respective enemy theme during their turns. Weather effects caused by CO powers can even last up to 3 days.
 * Also happens when Will/Ed appears in the middle of Hope Rising to save everyone from . His normal theme plays, yet before he arrives, you have no CO, so you have the no CO theme until he rolls up.
 * An observed property of the upcoming game Fable II is that the more rhythmically you kick ass, the more awesome the BGM becomes.
 * The Legend of Zelda: The Wind Waker is like this too.
 * Star Fox has Star Wolf's theme which remain pretty much the same (just with different instruments) throughout the series. You can't have a Star Wolf theme without Star Wolf team after all!
 * Including a Mariachi Band in Star Fox Assault and Super Smash Bros. Brawl.
 * Super Robot Wars uses this by default. The music that plays during any unit's Attack animation is often it's series theme song. Same for the non-Badass Normal characters in the Original Generation games, until the remake gave everybody their own. In all SRW games, they will also play the trope completely straight at appropriate moments in the plot, and will play an entire game's theme song when some serious beatdown is about to commence. Through the Alpha and OG series', Elzam Branstein's "Trombe!" is so Badass, overrides almost all other theme music (even bosses), and results in much ass-kicking. Particularly from Alpha 3 onwards, there is the option to change the unit's battle music, with exceptions (such as "Goldion Hammer" and "Goldion Crusher", which only play during their attacks -- their Badass attacks). In addition, the Sound Force from Macross 7 literally defeat enemies by singing at them -- and can also power up your other units with their music.
 * Though, of course, that was rather the point of Sound Force. Up to and including powering the Wave Motion Gun of the show by the end.
 * The spin-off game Endless Frontier also uses this liberally: while the normal battle themes are randomly selected from 4 different possibilities depending on who's in the party, the character-specific theme starts playing whenever someone uses one of their special attacks.
 * SRW manages to take this to a true extreme in Alpha 3 when a song composed as a collaboration between Minmay and Basara (in the story, at least) actually saves the day in  It's no coincidence that the song was created in Real Life by JAM Project for that game.
 * Sorry, I can't hear you over the sound of how TROMBE! I am.
 * Interesting to note, "Trombe!" was not the first instance of theme song override in the series. In Alpha Gaiden at least, certain units had "super attacks" that would trigger a different song. "Satellite Cannon", "Riders In the Skies" and "Dark History" were not programmed to have a lower priority than boss songs.
 * Ruri invokes this by playing the Gekiganger3 theme during a key battle in Super Robot Wars W, giving everyone the extra dose of Hot Blooded they need to save the day. Sousuke and Heero try to resist this, as they must be stoic.
 * Sheryl, in Scenario 18-A of Super Robot Wars Z 2: Hakai Hen, sings "Iteza Go Go Kuji Don't Be Late" to pump up the heroes so much that they all instantly shoot to 130 Will and beat the Beastmen mooks. Baron Ashura arrives with some Kikaijuu, so Ranka takes the stage and sings her song "What 'Bout My Star?". Simon and Kamina get pumped up even further, to the point that Kamina debuts Gurren Lagann's famous Giga Drill Break(er), nearly obliterating the Kikaijuu Taros D-7 with it
 * And, in the spirit of SRW, Battle Moon Wars does the same thing. Villains will always override songs with their own themes when they are engaged, and several characters have their multiple themes. For example, Shirou's default music is the one used for Fate Stay Night characters, but when using Nine Lives Blade Works, it changes into a remix of Emiya.
 * Speaking of song overridings, Dynasty Warriors have Lu Bu, which Elzam seems to be an Expy of. And finally, in Samurai Warriors, there's Honda Tadakatsu for the man of theme song overriding. Note that the music only overrides the 'default' music (it varies based on the situation) when a player is within proximity of either, and of course that this only applies when they're opposing NPCs.
 * In Samurai Warriors 2 Empires, the default theme for the stage is changed to Tadakatsu's theme while you play as him. You can still change it to something else if you wish.
 * In the best scene in Super Smash Bros. Brawl's Subspace Emissary, after The music being Dramatic Latin Chanting doesn't hurt.
 * Boss battles in Skies of Arcadia are accompanied by music that changes according to how well the player is doing. If the player's party has taken a lot of damage, the music is ominous and fractured; if the player is only a few turns from victory, it's upbeat and triumphant.
 * The final boss battle in Persona 3 is accompanied by a remix of Burn My Dread, the game's theme tune. It's appropriate for this trope because.
 * Pretty much all the music in Persona 3 was awesome, but every version of Burn My Dread has the ability to either rock you in the face or punch you in the soul. The version in the final battle is incredibly tense, but also uplifting, with the slow rise of the chorus in the background and the solid, rhythmic hip-hop lead vocals creating this eternal escalator of pumped-upness.
 * The boss battle against The Dragon, and true (non-scripted), is fought at the sound of "Battle Hymn of the Soul" --a glorious power-rock remix of the Leitmotif for the entire Persona series, "Aria of the Soul".
 * Alternatively, when you're visiting P3's town on the sequel, the ambient music is from the third game. Crowning Moment of Heartwarming for those who loved the last edition, and a brutal change from the original pace of the game, which is heavily pop influenced.
 * In Phantasy Star III, the world map theme adds instruments and background to the main melody as more characters join your party. However, if the main character of the generation falls in combat, a much more tense and negative tune plays until said character is resurrected.
 * This occurs at least once in each chapter of Live a Live, usually using that particular chapter's battle music. A notable example is during the Mecha chapter's giant robot Buriki Daioh (whose theme music is acknowledged by an NPC saying "Start the music!" whenever the player tries to activate it). Also notable is that the game's main theme is used as the battle music for the final chapter, making nearly every battle a Theme Music Power Up.
 * Also inverted in one chapter.
 * Saga Frontier had Alkaiser's theme, which plays
 * Musical motifs from Exdeath's already evil and imposing theme in Final Fantasy V are used in his even more awesome personal battle theme.
 * During an optional boss fight near the end of the game, a certain song starts playing when it becomes apparent that the party can't win. The song is, and sure enough he shows up to save the day.
 * In Age of Mythology, when the player's units attack an opponent's major buildings (Town Center, Palace, etc.) the music switches to a more stirring track.
 * Grand Theft Auto.
 * In Thunder Force 5, as you fly into space you encounter a replica of the ship you flew in Thunder Force 4 as a boss, accompanied by an (even more) awesome remix of the heavy metal theme tune of Thunder Force 4 (although this could be considered an inversion, considering its a Theme Music Power Up for your foe).
 * Captain America and The Avengers would play a cool Super-Hero type music when the level's boss was down below 30% health.
 * Played for laughs in Monkey Island 2, when Guybrush swinging heroically to grab a chest prompts the Indiana Jones theme tune. Then it's quickly subverted as Guybrush is left hanging from the rope and the music meekly fades out.
 * In the arcade game Fate/unlimited codes, when Archer gets to the "Yet, these hands will never hold anything" part of his chant, the regular background music cuts off and kicks in. Unlimited Blade Works ownage follows.
 * This happens in the original Visual Novel as well. As soon as Emiya starts playing, ass will be thoroughly kicked. By Shirou, a good 90% of the time. If Asskicking was a country, "Emiya" would be the national anthem, and Shirou would be the Grand Emperor.
 * It's difficult to say whether Kratos' theme music in God of War is this or a particularly bloody version of Mickey Mousing. Either way, it's awesome on spoons.
 * "Rage Of Sparta" from God Of War III definitely qualifies as this, as when it kicks in, Kratos is about to fuck somebody up.
 * In Space Invaders Extreme, picking up a powerup remixes the music into something louder and more intense for the duration of your powerup, and the music becomes even more epic if you go into Fever Time.
 * The final boss battle of La Mulana begins with normal-sounding boss music...which gets replaced by a remix of the Surface music, "Good Night Mom," in the boss's subsequent forms.
 * It was an interesting touch on the developers' part that all of the boss themes in the game open with the same chord sequence, with some remixing between each theme... except for the theme for the final boss's true form, which instead shares it's first few notes with an alternate version of the main ruins theme that only plays the first time you enter the ruins.
 * In Cave Story the battle with has three different songs. His first form is accompanied by "Gravity," the normal boss music. Then when you reach his second form, the music switches over to "Eyes of Flame," which is usually reserved for more dangerous bosses. Finally, his third and fourth forms come with a side of "Last Battle," the background music to the battle with the Undead Core.
 * In Final Fantasy IV, when Big Bad Zeromus has all but obliterated the party, the Elder of Mysidia clears his throat, asks all the former party members for help, and "Final Fantasy", the theme song for the entire series (also known as "Prologue") plays. Cue the Combined Energy Attack that revives the party to full fighting strength.
 * The Final Battle of Okami. The protagonist: Amaterasu, Sun Goddess. The enemy:, Lord of Eternal Darkness. The name of the song: "The Sun Rises." Yeah, the Final Boss doesn't stand a chance.
 * In the game God Hand, the song that plays in the first level, the western-style one is an awesome surf song called "Gene's Rock-A-Bye". Whenever Gene unleashes his God Hand, a much faster version of "Gene's Rock-A-Bye", called "Broncobuster" plays, even drowning out the themes of bosses he's fighting. Even Azel, who has the Devil Hand and his own Theme Music Power Up (from "Devil May Sly" to "Duel Storm") can't win against "Broncobuster".
 * Grand Papillon (AKA Joachim Valentine) from Shadow Hearts: Covenant plays this semi-straight several times throughout the game, and parodies it in one scene.  The parody comes from the fact that the mask in no way helps him -- it's all in his head.
 * The Space Channel 5 games also feature this trope. In the first one at the end, when Ulala is fighting, the music starts with a small, acapella version of the game's theme song "Mexican Flyer". The better Ulala does in the battle, the more voices join in with the singing. As she gets closer to winning, even real instruments start to play, finally culminating in a thick and triumphant rendition of "Mexican Flyer" as Ulala defeats the Big Bad.
 * Similarly, the final battle of the second game, Space Channel 5, Part 2 features Ulala fighting against the new Big Bad named Purge. The song that plays there is called "Connected Hearts" and is also a triumphant rendition of "Mexican Flyer", complete with the characters singing lyrics to it!
 * Play with the Spartans in Sid Meiers Alpha Centauri, and every time your troops are fighting you'll hear an absolutely badass heavy metal theme.
 * Rise of Nations replaces the usual ethnic rhythms with military fanfares every time your troops are kicking some enemy ass.
 * As well as Command and Conquer: Generals.
 * While you can choose the music playing in the earlier Command and Conquer, in Tiberian Sun: Firestorm, when Cabal activated his last line of defense, a huge and powerful Humongous Mecha, the song "Slave To The System" immediately plays unless you switch off the music. This applies for both GDI and NOD versions of the mission.
 * Also in Red Alert 3, the background music immediately changes when the player's unit is engaging the enemy in battle (and likewise changed again when the battle ends, to different songs depending on whether you won or lost).
 * Def Jam: Icon is the literal embodiment of this trope. When two players fight, they each choose a song. Whomever is winning the fight will have "their" background music playing (and the background shimmies and dances to its beat). Certain areas of the level explode during bass hits, and the fighters actually control the music by making DJ scratching motions in the air to wound their opponent. See how it works here, though the lyrics are NSFW.
 * Wangan Midnight Maximum Tune marks the introduction of a major character into an arc-ending race with his or her Leitmotif.
 * Keeping up with the Final Fantasy references, the last true boss of Final Fantasy X is heralded by a massively muscled arm clawing up to a platform -- and much more importantly, metal guitar.
 * The "Challenge" soundtrack really comes into its own as a TMPU in the way it builds up in the cutscene in The Beyond and its peak when the fight against finally begins.
 * In Shadow of the Colossus, the music is usually a mournful, slow-moving tune when you start fighting a colossus, but when you grab onto the thing and prepare to stab, the music swells into a louder, (usually) faster, and more awesome song that certainly fits the theme of you stabbing a thing well over 10 times your size to death.
 * Link gets one of these in The Legend of Zelda Twilight Princess whenever he gets in the position to actually hurt the boss.
 * In Elite Beat Agents, the agents fight off against music-hating aliens by getting everybody in the world to dance to an absolutely epic cover of The Rolling Stones' Jumping Jack Flash. In fact, the entire game (as well as the Ouendan series it's based on) revolves around this.
 * In Ace Combat Zero, whenever something particularly awesome happens the latin guitar from the final boss fight kicks in for a short duration. And of course there is that final boss music.
 * Ace Combat 5 has "The Unsung War", which combines your theme song with Ominous Latin Chanting for 7 minutes of awesome. Did I mention the fact that you're shooting down a SATELLITE while being attacked by the best aces of the last war?
 * In the original Persona, during battles where a new party member is introduced, the game uses a special battle theme called "Awakening". In these battles, the character(s) in question go from being regular high school students to full blown Magic Knights.
 * The original Star Soldier Shoot Em Up for the NES changes the music when you power up...and in a later remake for the PS 2, GCN, and PSP a rock remix of the power up theme plays. AWESOME.
 * Persona 4 has music for the Final Boss that starts out slow and ominous, then gradually picks up as you wear down the boss. The last stage of the music is an instrumental arrangement of the main battle theme, Reach Out to the Truth.
 * In Guilty Gear 2: Overture whenever one player gains a clear upper hand their character's theme music plays.
 * Also, special music plays when certain characters face off in a Master vs. Master battle.
 * The Wild Arms series, with the exception of the first and third games, have a tendency to have the game's theme song serve as the final boss's BGM. Possibly among the most awesome usages of this trope; Wild Arms 2 and Wild Arms 4 in particular use The Power of Friendship and a Combined Energy Attack completely shamelessly in the course of the fight, which when combined with the incredible songs makes for moments of total awesome.
 * Wild Arms 2 also has Nightblaze/Knight Blazer, the protagonist's Super Mode. When triggered, it overrides the current music with an ass-kicking beat, no matter how dramatic a boss you're supposed to be fighting. The exception is the final boss which, as mentioned above, has its own Super Mode with its own Crowning Music of Awesome.
 * The World Ends With You. You're about to face down the final boss alone, leaving you practically powerless. Suddenly, your friends decide to stop being unconscious and help out. Cue the Surreal Theme Tune.
 * In the console version of Blaz Blue, if a player performs Bang Shishigami's Furinkazan super move, the music suddenly changes to a brand-new song by Hironobu Kageyama called "Omae no Tetsui ni Kugi wo Ute". It's an over-the-top song about how much of a Hot Blooded Badass Bang is. And it is awesome.
 * BANG BANG BANG BAAAAANG!!!
 * Also, the final battle in story mode, rather than simply playing the same final boss theme as arcade mode, instead has the game's opening theme as its BGM.
 * A similar thing happens in Continnum Shift's True Ending as well, except it happens twice. First it plays Calamity Trigger's opening theme when the main character gets his Eleventh Hour Superpower. Then it plays Continnum Shift's opening theme against the True Final Boss.
 * And in the console version of the sequel, Continuum Shift, when you perform an Astral Heat (basically the game's version of a Fatality), the chorus of the opening song plays in the background.
 * Disgaea is fond of this. An interesting point is Kurtis' awesome, which makes the music his theme by default.
 * Also, the anime switches to an instrumental version of Lord Laharl's Hymn whenever the Prince gets angry. But that's nothing next to what does when their theme music is first played.
 * Tales of the Abyss has this used against the party in the optional Arena battle with four previous Tales characters; at first, the game is playing "Everlasting Fight," which is a medley of previous Tales battle themes. If you don't defeat them fast enough, Reid will activate Aurora Wall...


 * ...revive any of his fallen party members, deal tons of damage to you, and a remix of "Eternal Mind" suddenly starts up. This is about when any average player goes "Oh Crap."


 * In Baten Kaitos Origins, the True Final Boss knocks the Power Trio on its ass a few minutes into the fight, but then, 'Le Ali Del Principio' starts up, and the trio get back on their feet. And this time, you know it's going down.
 * Earlier than that, the songs 'The Power of a Pure Heart and the Path to the Distant Future' and 'Bitter Enemies in the Same Boat' are both used at powering-up points (namely,, respectively).
 * The final boss of Devil Summoner 2: Raidou Kuzunoha VS King Abaddon, comes in three stages. The first stage has a unique battle theme, the second is recycled from earlier, but the third plays Raidou's theme, as a nice reminder of just how epic he is.
 * The themes of the final boss isn't about how grand he is as much as it is about Raidou kicking his ass.
 * Inverted much to any Survivor's dismay by the Tank's theme in Left 4 Dead and its sequel.
 * Can be taken one step further once you figure out how to change the music that plays when a tank arrives. Switch to something with Ominous Latin Chanting for extra effect.
 * COME ON AND SLAM, AND WELCOME TO THE JAM!
 * Tales of Symphonia: One of the playable characters, Kratos, has his own theme tune that plays slowly. However, during a certain event in the game, a faster, more upbeat and more complex version is played.
 * The Double Dragon title theme is played during the final battle in the first game instead of the usual boss theme. Return of Double Dragon (the Japanese version of Super Double Dragon) is the only other game in the series to do this as well.
 * Oddly, in the NES version, the music switches to the City Slum theme when you fight Jimmy.
 * The battle with Willy in the arcade version of Double Dragon 2 uses a Boss Remix of the title theme.
 * Oddly enough, the original double dragon theme starts playing within a song in Dragon Force's Black Fire, and IT IS GLORIOUS!
 * One of the best things about Half Life 2 is that music is only played in certain situations, the rest of the game is devoid of BGM. This usually translates into intense battles cranking things up to 11 by adding music. The mad dash through the canals in the Water Hazard chapter or the showdown with the strider in Episode 1 comes to mind.
 * You can gauge whether or not it's safe to let your guard down by whether or not the music's still playing.
 * No love for Episode 2, when every alarm goes off in the underground?
 * Final Fantasy XIII has one for the battle theme; a lively D&B arrangement.
 * Bayonetta: Fly Me to the Moon.
 * Whenever a character enters Border of Death mode in Touhou Soccer 2, the character's accompanying theme takes over as the BGM briefly (assuming that a theme exists).
 * Gengetsu, the Bonus Boss of Touhou: Lotus Land Story gets a remix of the game's title theme. Needless to say, this is your signal that the fight will be a little intense.
 * An Easter Egg in Touhou Hisoutensoku includes this. If Reimu is able to successfully pull off the Fantasy Heaven spell card in Round 3 of a fight, a remix of her theme (only accessible through that spell card) plays in addition to a 330-hit instant KO.
 * And from the "mainstream" Windows Touhou games, Yuyuko, the final boss of Perfect Cherry Blossom, gets one of these when she activates her final spell.
 * Used as a game mechanic in Beat Hazard, the more intense the music you plug into it, the more powerful and more spread your shots are. You can also grab volume up powerups to make it that much better. On the other hand, intense music makes explosions larger and makes enemies and their shots that much harder to see.
 * In Pitfall II: The Lost Caverns every time you grab a treasure or rescue someone a galvanizing, heroic, upbeat theme vaguely reminiscent of the Indiana Jones anthem plays. One of the oldest ones in the book, as it was the first console game to feature PSG music, in fact the only 2600 game to have a custom sound chip.
 * Also whenever you hear Reunion in Threads of Fate. Expect something awesome will happen
 * In Bomberman Generation, the boss battles start off with a slower, more foreboding version of the game's Theme Song. However, when the titular hero brings a boss's health down to critical levels, the music changes to the main theme.
 * In Pokémon Black and White, when you've got the Gym Leader down to their last Pokémon this music cues up.
 * N's Last Battle theme.
 * The final boss of Ikaruga cuts the music for its final form and starts up "Stone Like", a remix of the first level's theme. As an added bonus, if you play your tennis right, the boss explodes right at the end of the musical phrase.
 * Meridian Dance plays when the Sword is finally revived in Secret of Mana.
 * In Dragon Ball Z Raging Blast 2, when you activate Raging Soul, the battle music turns from normal to the theme song sung by Hironobu Kageyama.
 * The Medal of Honor series and it's cousin the Call of Duty series will usually have the most dramatic music possible occur as you charge headlong into battle.
 * Especially when storming Fort Schmerzen at the end of Allied Assault, and driving the King Tiger tank in the fifth mission.
 * And Operation Repunzel in Frontline.
 * The Big Bad of Frontline, Rudolf von Sturmgeist, gets this when you board his train, and during the final battle with him.
 * The N64 / Play Station Mission Impossible game powers up the MI theme during the Embassy Escape, Tunnel, and Gunboat levels.
 * The true final stage of Raiden IV uses a remix of Raiden II's first stage theme, and the True Final Boss's theme is a metal remix of the Raiden 1 boss theme.
 * The River of Souls stage in Turok 2 uses an extended remix of the game's title theme. In the sound test, there's another unused remix that was apparently intended for the Final Boss battle.
 * The final battle music in the original Syphon Filter is an epic, albeit dark, remix of the series' main theme. Even more prominent in Omega Strain, eg Carthage Mall, and Belaya Vezha, both of which also feature Cherubic Choir / Ominous Chanting.
 * Twisted Metal 3 reprises "Meet The Creeper" for the final stage.
 * The theme song to the show-within-a-game Split/Second. Plays during the Elite races, which will most likely be the point of highest tension. Dynamically changes as you pull ahead or fall behind. Only serves to make whatever victories you can pull off against the most springy of Rubber Band AI sweeter.
 * The True Final Boss of Blaster Master reuses the epic Stage 7 theme.
 * Saints Row the Third has -three- Theme Music Power Up moments. "Power" by Kanye West plays when you Later, in a wrestling match with the head of the Luchadors, Killbane, and you have to fend off a ton of his lackeys with a Chainsaw Good, you get You're The Best Around. Finally,
 * Child of Eden fully powers up "Heavenly Star", the Genki Rockets' Signature Song, at the end of the final battle, after two remixes of it in the preceding Boss Rush and Sequential Boss battle.
 * In Sengoku Basara when either Ieyasu or Mitsunari face off against each other in the end of their story paths, "Naked Arms" will play in the background. Also, characters will have their Leitmotif play whenever they're fought.
 * Inverted in the final boss fight of Nie R, where the Shadowlord's very powerful theme gets weaker and weaker as the fight progresses until all that's left is a music box rendition of his theme for his final sliver of health.
 * In The Elder Scrolls V Skyrim, "One They Fear," a triumphant version of the main theme that occasionally plays during boss fights, certainly feels like one if you can beat the boss before the song ends.
 * The last stage of PN 03 uses the full version of the attract/intro music.
 * In Winback, the final boss battle with Cecile reuses the opening theme.
 * Asura's Wrath, in both a Moment of Awesome and a Heartwarming Moment, has Surge of Mantra, which is played upon
 * In Bleach the 3rd Phantom, whenever a character activates their Bankai, an instrumental version of the game's theme song plays. Same with the cutscene where you acquire (depending on Free Time choices) either Rengoku, Rasen, Shunko, or

Visual Novels

 * Shinkyoku Soukai Polyphonica features many in-universe examples of this, since the series is based on Magic Music, which really does power the spirits up.
 * Maji De Watashi Ni Koi Shinasai:
 * Men are about courage, bgm that was played each time Yamato or any other male character get their Moment of Awesome.
 * Sword Dance, bgm that was played each time Mayucchi get serious in her battle.
 * Bushi, song that was played during the battle between Momoyo against three deva of the martial art.

Web Comics
"Namine: Okay, we stopped Cloud, but do you think there might be a reason that this song was on Axel's murder mix CD?
 * The Adventures of Dr. McNinja has to sing along to the Ghostbusters theme in order to empower himself to do battle with ethereal beings. Not the lyrics though, just the tune: "Dada, Dadadada!" The technique is common to all ninjas, although methods vary; only the Doctor actually requires the Ghostbusters theme specifically.
 * When Aerith and Zexion played One Winged Angel in the murder-off in Ansem Retort, it was intended to stop Cloud. They didn't figure out until too late that it was also Axel's Theme Music Power Up.

Zexion: Oh shit...

[cut to Axel setting everything on fire]"


 * For a webcomic, Homestuck has a lot of songs used in this fashion for flash updates, but the best example is probably "Sburban Jungle", which was first used for the Loading Screen when John installed Sburb. However, it gets remixed for both the End of Act 3 and Act 4 animations to signify that some seriously awesome shit is going down.
 * Dave's theme song, Dave Fucking Owns At This Game, appears to have been promoted to an all-purpose power up theme song, as it's been renamed Upward Movement and features prominently in the End of Act 4 animation.
 * John's theme, Doctor, gets the same treatment, eventually being hijacked by Jade in Cascade.

Western Animation

 * The Real Ghostbusters. The chorus and some of the instrumentals from the Ghostbusters theme song would sometimes play, typically starting during formulation of the plan (which is usually Crazy Enough to Work) to defeat the episode's Big Bad, and then afterwards during the Final Battle with the Big Bad itself; which often also involved Egon coming up with a brilliant Indy Ploy during combat.
 * The Popeye cartoons, with Popeye's spinach-induced theme music, make this Older Than Television.
 * The heroes of most shows in the animated DCU. In one episode of Justice League Unlimited, Green Arrow even sang along to his theme as he kicked butt.
 * In the Justice League episode "Hereafter", Batman fights Kalibak while a fairly quiet orchestral version of the 1966 TV theme song plays in the background.
 * The Joker in Batman the Animated Series would hum his own theme music on occasion.
 * A particularly awesome example comes from the Batman Beyond episode "Disappearing Inque". Terry gets kidnapped by the villainess Inque, and she threatens to kill kim unless Bruce shows up. Later on, we see a large figure in a trench coat walking towards Inque... which turns out to be Bruce, in a massive Batman mech suit. The moment he starts whaling on her, an orchestrated version of the Batman theme from Batman the Animated Series starts playing.
 * Something similar happens in another episode where Bruce, rejuvenated by a couple dips into a Lazarus Pit, fights side-by-side with Terry, with the BTAS theme going, except it's electric guitars instead of trumpets soaring.
 * Parodied in the South Park episode "Towelie", as whenever the titular Towelie got high, Popeye's theme music played and Towelie became dumber than he already was.
 * Most of Kim Possible's flipping, fighting, and swinging is accompanied by a guitar-and-strings action Leitmotif that's re-used in every episode. A few of the recurring villains also get their own theme music; the mini-episode "Adventures in Rufus-Sitting" features a four-way fight in which the soundtrack changes several times in the space of a few minutes to reflect whichever combatant currently has the upper hand. Check out this clip.
 * The Futurama OVA "Bender's Big Score" has the climactic battle with the theme playing the background.
 * The fifth season finale of Teen Titans (not counting the last-last episode) has a particularly stirring version of the show's theme playing during the final battle with the Brotherhood of Evil.
 * Played at the climax of "The Drill" in Avatar: The Last Airbender, as Aang hands Azula one of her few outright defeats in the series.
 * Not to mention during the Season 2 Finale, any time Aang enters the Avatar State, and most especially during the climactic fight with Fire Lord Ozai. One of the coolest versions ever actually plays during the end credits after the series wraps up.
 * Side note: Aang's theme song is actually a remix of the main theme.
 * Same motif is played during a flashback episode featuring Aang's predecessor, Avatar Roku, describing the amazing power he became master over when he learned all the bending arts.
 * Transformers the Movie has "The Touch" by Stan Bush, most memorably played during a Foe Tossing Charge by Optimus Prime, and also when the Matrix of Leadership is opened near the end of the movie. Some fans theorize that Megatron and the Decepticons also received a power-up from "Instruments of Destruction" during the attack on the shuttle where they killed Prowl, Brawn, Ratchet, and Ironhide in about ten seconds. One can probably make an argument for "Dare to be Stupid" for the Junkions.
 * Optimus Prime of Transformers Generation 1 still has "The Touch" in "The Return Of Optimus Prime" when he opens up the Matrix of Leadership to wipe out the Hate Plague. His eventual successor, Ginrai, gets the rather cool "Don't Cry".
 * Transformers Cybertron gave us the instrumental song "Our Ally". Ass-kicking ensues whenever it plays. It has been favorably compared with The Touch. It most notably accompanied.
 * In Thunder Cats, Lion-O got to trigger his own theme music when he powered up the Sword of Omens. Ta-ta-TAA! And not only did he get to start kicking ass, but all the other Thundercats, no matter where or how captured/restrained they were, could see the Lion-signal, hear the roar, and naturally break free.
 * This also applies to the other Thundercats with their own Leitmotifs any time they're kicking ass individually. Panthro's can be especially epic, as the Leitmotif itself gets powered up if he's doing his ass-kicking in the Thundertank.
 * In the first two season finales of X-Men, a particularly rousing take on the show's theme backs up the heroes in the final battle. Then the third season started applying it to roughly every other fight they got into, and it kind of lost its potency.
 * Likewise, He-Man's transformation sequences are always accompanied by stirring theme music, no matter what incarnation you're referring to.
 * Even in the Live Action movie, where He-Man has no alternate persona and therefore doesn't have a transformation sequence, gets a musically enhanced Power Up when necessary. He Has The Power!
 * In Code Lyoko, William gains a personal music theme in Season 4 . It follows him in each of his subsequent appearances, which are generally the most intense fights in the show. (He isn't always victorious, though.)
 * On Lyoko, the sound effects seem to be having fun whenever the gang's about to win or lose.
 * Inspector Gadget used this all the time: a version of Penny's theme would often play just as she's about to turn Dr. Claw's newest scheme upside down. Brain would occasionally get these as well, but less often (more often his theme would be played during particularly funny scenes).
 * Any time that Captain Planet is summoned. Most of the time it's the title theme, but there are a couple of other music cues that are equally awesome.
 * In the first episode of the '80s Ninja Turtles toon, the turtles discover that the Foot Ninja they're fighting are actually robots, and the theme music starts up as they proceed to go to town on them.
 * The Eighties loved this one. On Galaxy Rangers, once you heard the electric guitar music, you knew something awesome was coming in.
 * On Lilo and Stitch: The Series, the show's theme song "Aloha E Komo Mai" would usually play in an upbeat rock format whenever Stitch or someone else was kicking major butt.
 * Whenever Mario (and/or Luigi) powered up in Super Mario Bros Super Show, the transformation was accompanied by the "level clear" fanfare from Super Mario Bros 2.
 * In The Big Knights, whenever Sir Morris and Sir Boris are about to perform their idea of heroics (which usually means smashing everything), the show's thunderous orchestral theme music kicks in.
 * The season one finale of Generator Rex uses the theme tune when.
 * In the first Shrek film, the familiar strings of Joan Jett's "Bad Reputation" start to play when things start to turn in the titular ogre's favor during the wrestling match in Duloc.
 * Probably an odd case combined with He's Back in Shrek2, when Shrek, Donkey and some of the others race to rescue Princess Fiona while the Fairy Godmother's singing "Holding Out For A Hero".