The Day the Music Lied

The Hero is squaring off with the Big Bad. His theme song picks up and all doubts are cast out of your mind as he moves in to attack. Some ass kicking is GUARANTEED once that starts playing. But all of a sudden... No! The hero is soundly defeated! It looked like such a sure thing! It looks like today is The Day the Music Lied.

The name of this trope is a reference to The Day the Music Died, as recounted by Don McLean in the 1971 song "American Pie".

If played for laughs, expect it to be accompanied with a Record Needle Scratch or a fading to bass or even a duck call for extra humiliation.

Compare Cat Scare for when dramatic tension is build up with music only for a harmless outcome. Related to the Hope Spot.

Anime and Manga

 * Bleach uses it a few times, most notably when Aizen stops and nearly bisects Ichigo with a single finger in the middle of his theme song, and again when the exact opposite happens much later: When Ichigo barehandedly stops Aizen's sword in the middle of the "Snakes of Despair" song.
 * The battle against Aaroniero featured the villain's catchy, upbeat theme music playing... while he was on the floor dying in agony and begging for his life.
 * Tengen Toppa Gurren Lagann features this in episode 25.
 * Episode 3 as well, to some extent: Viral launches a volley of missiles at the Gurren Lagann and the battle music immediately goes silent even though the GL is barely damaged.
 * Episode 8 subverted this: and screams his head off. Cue the sad music and his teammates going Mass Oh Crap... until he turns out to be alive..
 * Hajime no Ippo does it in Ippo's Title fight against Date.
 * One Piece does this a few times, particularly with Usopp.
 * Team Four Star's Dragonball Z Abridged, when Yamcha arrives to fight the Saiyans. He gives his fellow warriors a roguish grin, heroic music begins to swell in the background, he starts his Rousing Speech, and BOOM.
 * "SKREEEEEEEEEEEEEEEE!!"
 * Digimon plays this trope for laughs whenever the titular characters try to digivolve while hungry.
 * One notable serious example is in episode 26 of the first series, during Myotismon's first confrontation of the Digi-Destined. All of the Digi-Destined's Digimon attack Myotismon as "Brave Heart" plays. This music abruptly stops when Ikkakumon's Harpoon attack hits Myotismon and creates an explosion, seemingly taking him out, only for Myotismon to jump out of the cloud of dust and saying "Do you think you've won?", before proceeding to beat up the Digi-Destined's Digimon.
 * The second Digimon movie, Our War Game, has another serious example. "Brave Heart" starts playing as Agumon and Gabumon Warp Evolve into War Greymon and Metal Garurumon. When Infermon evolves into Diablomon and attacks Patamon and Tentomon as it's evolving, the music cuts out. When the two Ultimates/Megas go on a Roaring Rampage of Revenge, the music picks back up, only to start skipping on "show me your brave heart", signaling the connection's lag and War Greymon's weakening before it completely cuts out when Taichi crashes the computer.
 * Played with in Magical Girl Lyrical Nanoha As. During her first battle with the Wolkenritter, Nanoha is trying to use Starlight Breaker to open the way for reinforcements for her friends. During the charging, the music plays to the fullest... until a certain hand rises from her chest, absorbing her magical power. The subversion?. She still shoots. And it was glorious, accompanied by the music playing to the fullest again.
 * Pokémon does this occasionally, for example during Ash's final battle against Brandon when Charizard loses against Dusclops.
 * The most notable example is in the Japanese version, when "Mezase Pokémon Master" plays during Ash and Pikachu's battle against Gary and his Electivire, when this song gets abruptly interrupted when Gary's Electivire suddenly uses Protect to defend against a Volt Tackle from Pikachu, before taking it out with a Thunder Punch.
 * Sailor Moon,
 * In Macross Frontier, Sheryl falls into the cockpit of a VF and takes off to join the fight, her theme music starting up as she lifts off. Five seconds later, it comes to an abrupt halt as she's shot down.
 * In the Bakuman｡ anime, after Mashiro makes Azuki cry by asking her if they have to wait until their dreams come true to see each other, he tells Takagi he wants to submit something to the Tezuka Awards, and dramatic music plays, as it does when the characters get an idea or renewed determination. After Takagi suggests that he be more patient and make a good submission, the music fades as Mashiro apologizes. Then again, after Takagi learns that their first submission, The Two Earths, was not even chosen as a finalist, he decides to go with Mashiro's plan.
 * In Cromartie High School, "Freddie"'s leitmotif is this song, usually played up to the 3rd or 4th drum roll whenever he suddenly appears. Once, he startled someone, who shut the door on him, cutting off the music before the second bar was finished.
 * In Heartcatch Precure, Cure Blossom and Cure Marine decide to confuse the Desertian of the Week by running around it in circles really fast. At first, Cobraja, the one who made it, seems concerned... until he looks ahead as the music comes to a droning halt as Blossom and Marine have slowed down, eyes swirling and admitting that was a dumb idea.
 * Episode 55 of Fullmetal Alchemist Brotherhood:
 * The very well known third episode of Puella Magi Madoka Magica:

Film

 * Mighty Morphin' Power Rangers: The Movie Movie pulls something similar. As the team morphs for the first time in the film, we are treated to a pumped-up version of the theme song and obligatory posing, after which it is revealed that the bad guys have fled the scene during all the buildup. Even the post-reveal guitar riff sounds disappointed.
 * The theme charge of the Rohirrim cut short the moment the line met the Mumakil. Not pretty.
 * During Scott Pilgrim's first encounter with Gideon Graves, he dispatches Gideon's mooks accompanied by an up-tempo version of Sex Bob-omb's signature song, then leaps in for the kill ... only to be soundly smashed down by Gideon. Appropriately, the music segues straight into a video-game "you lose"-style 8-bit riff.
 * In Seabiscuit, during the historic match race against War Admiral, Seabiscuit jumps out to an early lead. After a while, though, he begins to slow, accompanied by mournful music, allowing War Admiral to catch up. But Seabiscuit slowing was a Batman Gambit on the part of his jockey, George Woolf, and (injured) regular jockey, Red Pollard, who knew that the horse would push himself harder if the other horse was matching his speed. It worked, and Seabiscuit won. This was, as Laura Hillenbrand's book described, Truth in Television (well, except for the music).

Live Action TV

 * Kamen Rider Agito pulls something like this. Sometimes, in the middle of a Theme Music Power Up, an enemy will counter Agito's finisher. When that happens, the music stops mid-song.
 * Happens all the time in The Amazing Race, most often playing the "elimination" music right before a team is told that it's a non-elimination leg.
 * A gag used in The Hitchhikers Guide to The Galaxy, when Arthur and Ford are trapped in the Vogon airlock, about to be blown into space. Ford says "No, wait! What's this switch!" accompanied by a hopeful swell of music.. only he's just being a jerk. There's no switch, and they do get blown out of the airlock.

Professional Wrestling

 * Is sometimes invoked when a heel is in the ring either mocking an absent babyface or ranting about his/her supposed invincibility. In the middle of the segment, the face's distinctive music will hit and the heel will affect an Oh Crap expression...only to start laughing when the supposed entrance of the face is merely 1) a fake-out orchestrated by the heel or 2) one of the heel's minions dressing up as the face for mockery. (See Edge and Lita's wedding for an example of the former and Michelle McCool calling Mickie James a fat "piggie" for the latter.)

Video Games

 * Crocomire in Super Metroid. After it falls into an acid bath which dissolves its flesh, its skeleton crashes through the wall and the boss music starts up again... then the skeleton collapses.
 * In Ys VI, after you defeat the first boss, it gets up again and the boss music restarts, but is interrupted when Olha kills it with an Emelas arrow.
 * In The Legend of Zelda: Wind Waker, Puppet Ganon has one of these. Upon the defeat of the giant puppet, the standard victory fanfare begins and the puppet rises towards the ceiling. Then, the music changes tune slightly, and Puppet Ganon morphs into a giant spider.
 * In The Legend of Zelda: Spirit Tracks, Link and Zelda celebrate the Power of Friendship after defeating a boss. The camera slowly pans around them, the background fades to white, happy music flares up...then the band stalls when the background returns to normal and you see the Not Quite Dead boss simply limp out of the room back to his master.
 * In The Legend of Zelda: Twilight Princess, the same thing happens with Armagohma. Link destroys it, the epic victory music plays, Link does that badass sword sheathe and...Armagohma's not dead. The music promptly dies, though what's left of the monster is laughably easy to defeat.
 * Chrono Trigger. A lowly villain brings forth a couple of monsters, the characters pull out their weapons, and battle music starts... then the monsters fall into a pit. Cue the music faltering out.
 * The game uses a variation earlier: enemies pop out, characters take their positions, the box doesn't pop up, the box doesn't pop up, the box doesn't pop up, then the music changes, their leader shows up and you have to race him.
 * Ace Attorney: "OBJECTION! ...I was hoping to come up with a question while I was objecting, Your Honor... I didn't."
 * 'Blaz Blue'. The butt monkey ninja has an awesome over the top theme that activates when you use Furinkazan which basically makes you super fast and near impossible to hit. Cue epic facepalm http://www.youtube.com/watch?v=U 158 VC 5 u 6 kk
 * In the first Mario Party, one board has Bowser giving players black stars. At first it might seem that they count because of the fanfare... Then they Let The Air Out Of The Band to let you know you were forced to pay for nothing.
 * Persona 4 does this with the True Final Boss fight.
 * Clannad often starts playing emotional music during scenes that are set up to be misleading either to the audience or characters. Such as Tomoya starting to tell Tomoyo that Sunohara loves her, or when Kyou pulls Tomoya aside to show him a love letter, the assumption being that it's from her to him. The music starts in both cases only to get cut short by Sunohara butting in to say he wants to fight Tomoyo or an irritated Kyou explaining it was from some boy to Ryou.
 * In the Uninvited game, when you meet the Scarlet O'Hara lookalike, the music sounds VERY upbeat. As if you're going to have a pleasant time. Doing anything aside of a select few will cause her to reveal her face as she rips you apart while said music turns into utter horror. This is noteworthy because usually dangers in the game were accompanied with an eerie music, rather than such upbeat music.
 * Final Fantasy XIII-2: the final boss is defeated and the game's theme music starts up (just as it did in the previous game).

Web Comics
"You attempt the rare and highly dangerous 5X CLIFFHANGER COMBO, and fail.
 * In Homestuck, after the protagonist John discovers that Fruit Gushers are a Betty Crocker product, he begins to have a mental breakdown - until the music squeals to a halt with the flashing words THIS IS STUPID.
 * Also happens in the flash animation where the Wayward Vagabond has a Race Against the Clock, where he has to escape with only seconds to spare. He almost makes it out in time, but slips on a ladder, while the music in the background slows to a halt.
 * However, this one's subverted (and promptly Lampshaded, of course), as the very appropriately epic song "Explore" accompanies the End of Act 2 immediately after.

We are doing it, man.

We are making this happen."


 * Once again in the 4/2/11 update, where
 * Of course, this example could also count as a Musical Spoiler. Chorale is one of the songs related to Rose (although it was originally Jaspersprite's Leitmotif),

Western Animation

 * In pretty much every Popeye cartoon, Popeye will eat spinach for some instant muscle power, with an accompanying Theme Song. However, the Theme Tune is abruptly interrupted when the can of spinach is taken away somehow (such as by an explosion, or some moving machinery). In one cartoon (How Green Is My Spinach), Popeye ate some other assorted vegetables but failed to get the desired effect (since Dangerously Genre Savvy Bluto invented a formula the wiped out the world's spinach), and in another (A Date To Skate), Popeye just plain forgot it. This makes this Trope Older Than Television.
 * Avatar: The Last Airbender pulls it off in the Season two Finale. Aang is rising into the air in all his Avatar State glory, glowing with holy light, and BAM. Sizzle. Azula shoots him it the back, and he sort of twitches. Then he falls over.
 * Justice League: The New Frontier. Superman, being Superman, rouses and unites a divided group of superheroes, then, with heroic music playing in the background, charges off to scout and engage the enemy...only to be hit with an energy beam so powerful it knocks him several miles back and into the sea, pretty much removing him from the movie (Supes doesn't save the day in this one).
 * The Boondocks: Stinkmeaner possesses Tom and tries to get his revenge on Robert...but then Huey and Riley jump in and Huey tosses Robert his belt as the show's theme starts. The three of them proceed to get their asses kicked while the music is playing.
 * A nonviolent version on The Simpsons: Abe Simpson is about to perform an act called the "Funky Grampa" - and just as he starts up the singing and dancing, he promptly falls asleep.
 * The Legend of Korra: when Korra starts trying to meditate, music starts to play for a second or two before being abruptly cut-off when she gives up on it.
 * In the South Park episode "Stanley's Cup," the kids' team is slaughtered by the professional team, only for "We Are the Champion" to start playing. Played With by the implication that the other team might have been the Hero of Another Story, congratulating themselves in the same way you would expect at the end of any sport movie.