Musical Episode

"Phineas: So what do you say? We’ll do all the same things, but we’ll break into spontaneous singing and choreography with no discernible music source!

Ferb: Hmmm.... What assurance would we have that everyone else would also break into song and do the same thing?

Phineas: I don't know. I think they probably will."

- Phineas and Ferb, "Rollercoaster: The Musical!"

Once in a while, a show will shake things up and do Something Completely Different. One way of doing that is by turning the show into a The Musical for an episode.

A Musical Episode is structured around the cast breaking into song (and possibly dance) throughout the episode. It might use an in-universe justification, such as a Battle of the Bands, some sort of weirdness, or a new character causing all this cheery singing. Alternately, it can play like a Broadway show where it's just taken for granted that some events will be dramatized through song and dance.

Opinions on a Musical Episode can differ wildly. Many will enjoy the up-beat, unexpected change of pace, while many will dis-like it for that very reason. Also, like any premise, the songs and choreography have to be good, or else you're doomed from the start.

Anime

 * One episode of Kure-nai depicts the characters' attempts to rehearse a musical for a local festival, which eventually leads them to come up with their own material from scratch. It turns out that.
 * Nadia: The Secret of Blue Water had a Character Song episode at the end of its infamous Island/Africa arc.
 * Kanamemo's fourth episode would be an amusing little story about the Fuhshin News employees attempting to get to the pool on its own, but the anime takes it a step further and adds song and dance numbers to the mix. No explanation is given for the singing.
 * If it helps, Kana is as confused as the rest of us.
 * One Piece: The TV Special Dance Carnival could be considered a dance episode (Dance special?). It starts on the aptly called Mirrorball Island. While trying to escape the Marines, Jango hypnotizes everyone to dance 'till they drop. Including the Straw Hats. Hilarity Issues.
 * The English dub of Duel Masters randomly has Shobu and Kokujo be forced to come up with an inspirational song before they can duel.
 * Bobobo Bobobobo's 48th episode had them defeat a foe by singing him into submission. Even by Bo-BoBo's standards, it's amazingly crazy.
 * Jewelpet Sunshine had the characters preforming West Side Story in one episode.

Comics

 * Nodwick had one of these, courtesy of Arthax and a "Scroll of Thespia".
 * The Doctor Who Magazine strip "Planet Bollywood" has the Eleventh Doctor and Amy land on a planet where everyone breaks into song and dance routines.
 * The ninth issue of Tomorrow Stories featured a Greyshirt musical, as in a literal stage production; Greyshirt: Indigo Sunset later established that the man himself took the title role at one showing. Critics are astounded at Greyshirt's singing and dancing, claiming that he could've been another Gene Kelly.
 * The story Deadbeats! from Hack/Slash Trailers: Part 2. It involves zombies invading Broadway.

Fan Fiction

 * Several of the Calvin At Camp episodes, notably the movie parodies, are musicals.

Film

 * Slumber Party Massacre II, where the villain is a spectral rockstar whose main weapon is an electric guitar outfitted with a drill. It's a very weird and random sequel.

Literature

 * Spellsinger, the fifth book of Avalon Web of Magic. A benefit concert and singing contest insert about three songs into the book...through just printing the lyrics in the text. Some of the songs were Defictionalized and released on CD to promote the book.
 * How Much For Just The Planet? by John M Ford is a Star Trek Expanded Universe novel in the form of a Musical Episode. All the songs are pastiches of pre-existing songs so they'll be recognizable in text. Unfortunately this also means that filming it would probably be a massive copyright violation.
 * The Dragonriders of Pern novels Dragonsong, Dragonsinger, and (to a lesser extent) Dragondrums, by Anne McCaffrey all are about harpers, so it's justified that she presents the lyrics to many of their songs. (This happens to a lesser extent in her previous Pern books too.)

Live Action TV

 * "Once More, With Feeling" from the sixth season of Buffy the Vampire Slayer - a fan favourite and Crowning Moment of Awesome. The episode bizarrely sends up the musical genre (and its respective subgenres) as a whole, musical and dance genres from rock to ballet, and (in typical Joss Whedon fashion) the series itself with wicked glee, yet also manages to fit plot and Character Development in as well and come up with a plausible (for Buffy) explanation for why everyone's singing.
 * THEY GOT THE MUSTARD OUT!
 * It was so well-known it made it into Channel4's top 100 musicals at number 13, above such notables as Les Misérables and The Phantom of the Opera...
 * Xena: Warrior Princess had two, actually. The funny one that parodied the "battle of the bands" type trope, and the (in some ways) more serious "Bitter Suite" episode.
 * That's So Raven did one in which Raven discovers that a talent scout is visiting her school, and thus everyone is breaking into song to impress the scout, whom they all mistakenly believe is the janitor.
 * Even Stevens did an episode titled Influenza in which Ren has a fever induced dream in which the whole school would randomly burst into song, and Ren herself had to sing a song in the climax.
 * "We went to the moon in 1969..."
 * "I've got chicken soup, delicious chicken soup soup ..." *cue Ren screaming in terror*
 * Scrubs did a musical episode (from the musicians of Avenue Q) based on the premise that a patient had an aneurysm that was making her hear singing when people talked. All the musical sequences were from her point of view, and after she goes into surgery, the music stops.
 * Seventh Heaven had a Valentine's Day episode that was also a musical, called Red Socks.
 * X Play, a video game review show, did a surprisingly not horrible musical episode.
 * Eli Stone has musical numbers in most of its episodes.
 * Malcolm in The Middle had an episode in which Dewey turns his parents fight into an opera. The episode is appropriately entitled "Dewey's Opera".
 * Lexx had its musical episode in Brigadoom. In it the crew of Lexx encounters a mysterious theater floating in space and ends up performing Kai's backstory on stage. Of particular interest is the use of theater-grade special effects, so that a fleet of spaceships is represented by people waving miniatures on poles instead of the show's usual computer-generated effects.
 * Actually, as the behind-the-scenes DVD material shows, some of the show's VFX were produced cheaply by manipulating miniatures on poles in front of a green screen, so the play version might be more of a self-referential parody.
 * Tracy Beaker did one.
 * That 70s Show's 100th episode was a musical called, quite predictably, That '70s Musical, only instead of singing songs written specially for the show, the characters sang some of the most famous seventies' songs, as well as the Turtles' "Happy Together" from the sixties.
 * Greys Anatomy had one. Similarly to the Scrubs example, it was from the point of view of a patient.
 * The Two Pints of Lager and A Packet of Crisps episode 'When Janet Met Jonny'.
 * Once in a while, in The Seventies, Mister Rogers Neighborhood would invite an opera singer friend of Mr. Rogers named John Reardon, and the episode, entirely set in the Land of Make-Believe and featuring a lofty plot line, would resemble a musical or light opera, with all of the characters singing their lines.
 * Sesame Street did an episode like this once.
 * The Kamen Rider Faiz Hyper Battle Video, where the characters suddenly break out into song and dance for no apparent reason as part of Smart Brain's latest plot. They Lampshade the fact that they're singing, and in the end Takumi ends up defeating the Orphenocs with a sonic blast from a radio which was causing the whole thing. And then Takumi wakes up.
 * Chicago Hope had the fourth-season episode "Brain Salad Surgery". Dr. Aaron Shutt suffered a brain aneurysm that caused him to hallucinate the rest of the hospital staff singing and dancing.
 * On the heels of the success of Glee, FOX had a musical week including Fringe. Which turned out to be a Noir Episode as well-- a double case of Something Completely Different. And it was justified in that the noir musical was simply the fictional story within a Framing Device.
 * Its Always Sunny in Philadelphia had its musical episode where Charlie actually wrote and then directed a musical, not that his friends would let it be that simple
 * Good Times had 2. One doubled as a Christmas Episode while the plot of the other was a talent show to raise money for a daycare center in their building.
 * Done in Star Trek Voyager and Star Trek Deep Space Nine.
 * Every episode of Glee. Justified because it IS show choir.
 * Ally McBeal had one at the end of season 3. Randy Newman wrote part of the music for this.
 * Oz has one of sorts. Series 5, episode 3 'Variety' has a central theme about variety shows and each of the narrator segments, usually occupied by Hill's musings about the theme is instead one of the characters singing in various different musical styles.
 * The second season of Community had "Abed's Uncontrollable Christmas" which, since it was also their homage to Will Vinton's Claymation Christmas specials, had several short songs, and the third season Christmas Episode episode "Regional Holiday Music" was a blatant Glee parody.
 * Every episode of The Fresh Beat Band. Justified because it is about a band.
 * Every episode of The Wiggles. Justified for the same reason.
 * Sanctuary had a musical episode. Justified because the reason they were singing was to communicate with Will's girlfriend, who had been.
 * The Land of the Luvvies episode in The Legend of Dick and Dom features a much-feared tribe of Luvvies who spread song and dance through the neighbourhood.
 * Little Howards Big Question has an episode called Can We Sing For A Whole Episode?.
 * Every episode of Cop Rock; justified what with it being, you know, a musical.
 * Smash; see above, plus it's set in the world of musical theatre.

Radio
"Evelyn: Oh no! You are going to sing!
 * Episode three of the Big Finish Doctor Who audio drama "Doctor Who and the Pirates". As the story is being told through the framing device of the Sixth Doctor and Evelyn telling the story to one of Evelyn's students, it already contains a bit of storytelling silliness (Evelyn doesn't remember all the pirates' names, so she makes up obviously fake ones for the less-important characters), but when the Doctor takes his turn at telling the story, he decides, for Large Ham reasons, to deliver it in the form of a Gilbert and Sullivan musical. You could say that he's the very model of a Gallifreyan buccaneer.
 * As far as Cliff Hangers go, this one is one of the most interesting:

The Doctor: Well yes! I am! Llaaa-]"

Web Comics

 * Penny Arcade did this at least once.
 * Instant Classic, which has had background scoring in it before, composed and created an actual musical number to play along with the comic as it was read.
 * Brawl in The Family did it five times, soon to be six. The first was for Christmas 2008, a parody of You're a Mean One, Mr. Grinch. The second was for Comic 200. The next three were for Christmas 2010, and the next one for Christmas 2012.
 * Narbonic had a brief interlude in one storyline to perform the Madblood Battle Anthem.

Web Original

 * Fans! did this -- complete with fully-voiced MP3s linked beneath the panels -- mostly as a homage to Buffy the Vampire Slayer. Again, there is Character Development as the cast is forced to sing their hearts out; in contrast to the generally painful revelations in Buffy, however, this mostly helps restore the characters' spirits, reminding them why they do what they do. The arc's title, "Makin' 'Em Sing", hints at the fact that the entire thing was orchestrated by people eager to learn what the cast have been hiding recently.
 * Homestar Runner had a Musical Episode in the Strong Bad Email Rock Opera.
 * Later parodied in portrait. Strong Bad announces that this email will be a musical email, proceeds to start singing the email, then gives up after a few words.
 * This little number.
 * Sailor Moon Abridged crosses this idea over with all Pokémon songs... The results are quite interesting.
 * Last Exile Abridged gives us this beauty, which is not terribly surprising given that Unwardil is a musician. She Who Must Be Obeyed later makes him summarize the episodes properly.
 * Princess Tutu Abridged did this for Episode 12. Everyone was going out of their vocal range and/or having trouble with character voices and still manages to be enjoyable. Particularly a song about the famed reveal and ensuing results.
 * The Legend of Neil did one in its second season.
 * The Guild has done a number of videos that could qualify as a Musical Episode.
 * The Batterys Down is a musical webseries, which means every episode is a musical episode.
 * The Dr. Steel Show, Episode 3.
 * I'm a Marvel And Im ADC did this in honor of their hundredth video. CONTINUITY!
 * Brows Held High did a David Bowie themed musical episode for the movie The Man Who Fell to Earth. This is probably the only internet review show to have this type of episode.
 * Not... quite...
 * Another one is Stuff You Like episode 10: a review of Les Misérables. To the tune of One Day More. In parts.
 * The Nostalgia Critic's Moulin Rouge review, which also featured cameos from The Nostalgia Chick, Brentalfloss and others.
 * The Twilight Chronicles - The Premonition is considered a musical episode, however, only one musical number ("All Out of Love") is featured. Spenser Doherty's song "Cup of Coffee" was overdubbed with the real song due to his off-key singing and Gen Borg just danced to her song.

Video Games

 * Musical Episode, huh? Try a Musical Boss Fight. "I, am, the Great Mighty Poo..."
 * "... and I'm going to throw my shit at you, a huge supply of thish, comes from my chocolate starfish..."
 * "... how about some scat, you little twat?"
 * Kingdom Hearts II also had a Musical Boss Fight, and a pretty good one at that. Sure, Atlantica's Unexpected Gameplay Change has caused a Broken Base, but nonetheless, the fight against  was nothing short of masterful.
 * In Chibi-Robo, almost everything you do causes a seemingly-random string of notes to play in addition to the background music.
 * The final boss of Chrono Cross, while not having any music playing while you fight, has you . If you speed footage of this battle up,.
 * The Nightmare Before Christmas Oogies Revenge has you defeating bosses with a singing retort going between the characters the entire time.
 * The entirety Epic Mickey 2 is reportedly going to be one of these.

Western Animation
""R-E-C-Y-C-L-E recycle!
 * Squidbillies: "America: Why I Love Her".
 * The Simpsons has done countless musical episodes, including "The President Wore Pearls", "Simpsoncalifragilisticexpiala(Annoyed Grunt)cious, "My Fair Laddy," "Yokel Chords", "Treehouse of Horror XX: There's No Business Like Moe Business." and "Elemental School Musical".
 * In addition, the show often parodies The Musical, especially All Musicals Are Adaptations. See the former article for more information.
 * There's also the Clip Show "All Singing, All Dancing," which highlights musical numbers throughout the first eight seasons. Almost all the framing sequences are entirely in song.
 * South Park has done many musical episodes, too.
 * Including The Movie.
 * The last third of Futurama's "The Devil's Hands Are Idle Playthings" is an opera. As sung by the cast.
 * Daria, of all shows, had a musical episode aptly named "Daria!" And yes, Daria sings too.
 * To be more accurate, she doesn't sing as such. More does the Rex Harrison talking/singing thing. Although her Dad and Trent have a killer heroic Duet...
 * She mainly talks in pitch instead of singing, but she does sing a few lines. Probably because she's just unmotivated, even in a musical. Perfectly in-character.
 * "School's Out: The Musical", an episode of The Fairly Odd Parents.
 * Except for possibly a few sentences, the entire episode "See Me Feel Me Gnomey" of The Powerpuff Girls is completely in song.
 * Which in this case makes it a Rock Opera. In fact, the title of the episode is a reference to The Who's Tommy.
 * Same with the Evil Con Carne episode "The Pie Who Loved Me" (though it was a significantly shorter episode)
 * Same with The Grim Adventures of Billy and Mandy episode "Little Rock of Horrors", which incidentally aired together with the above Evil Con Carne episode. It features a very catchy swing-type tune sung by a brain eating alien.
 * Which was sung by Voltaire.
 * Rocko's Modern Life had the episode "Zanzibar".

C-O-N-S-E-R-V-E conserve!

don't you P-O-L-L-U-T-E

pollute the rivers sky or sea

or else your gonna get what you deserve""

""Hellooo, dear brother! What have you got there?"
 * "And you know what they say..." - "It's going to be a song, isn't it?"
 * "We're a big unruly mob ..."
 * Rocko writers Dan Povenmire and Jeff "Swampy" Marsh noted that with every episode they wrote (including the above "Zanzibar") they tried to work in a musical number, even when there didn't need to be one. Guess what they ended up working on later.
 * Codename Kids Next Door did two musical episodes: F.O.O.D.F.I.T.E. (A heavy metal opera) and L.O.V.E. (A West Side Story-ish musical).
 * Pepper Ann had one. Pepper Ann was auditioning for a musical at school, fell off the stage, and blacked out; when she came to her life was a musical. It turned out to be a dream when she came to for real.
 * Arthur did a music video episode: just a series of musical numbers performed by the cast. It goes on about how wonderful libraries are. The songs range from the slightly embarrassing pseudo-rap "Library Card" to Brain's Crowning Moment of Awesome...
 * Kim Possible's "Rappin' Drakken" comes close to being a musical episode.
 * Danny Phantom includes an episode told mostly in rhymes, like a Dr Seuss story.
 * Ruby Gloom did an hour-long episode called "Hair(less): The Musical".
 * The Batman the Brave And The Bold episode "Mayhem of the Music Meister" is notable for having somewhat of an in-story justification: the story is about a villain with a hypnotic voice controlling the world through music. Probably the show's most audacious use of Refuge in Audacity.
 * Although that doesn't explain Black Canary (and later, Green Arrow), breaking out into song on their own. Maybe they're just musical theatre fans.
 * "Was the singing really necessary?"
 * It also helps that the Music Meister is voiced and sung by
 * Can be heard here.
 * Freaky Stories chose to tell the Urban Legend of "the Hook" as a Musical Episode.
 * Re Boot's recap of the third season in the last few minutes of the last episode (of the third season) does this.
 * Phineas and Ferb has one or more songs per episode, not joking, but there's a number of full-fledged examples:
 * "Dude, We're Getting the Band Back Together" has four songs, one of which was nominated for an Emmy.
 * The Christmas Episode would also qualify.
 * The "Wizard of Odd", a Whole Plot Reference to The Wizard of Oz, which has the added bonus of having it's Musical Episode status lampshaded at every possible opportunity.
 * "Rollercoaster: The Musical" is a full musical episode based off the plot of the first episode, where most of the catch-phrases and running gags get their own songs.
 * The movie "Across The Second Dimension" would probably also qualify, with eight songs, not counting the deleted one ("Mysterious Force").
 * Rugrats had an episode where the rest of the babies try to teach Dil to appreciate music. To do so, they sing their own renditions (complete with reworked lyrics) of classic songs such as "Bicycle Built For Two," "You Make Me Love You," and "Pack Up Your Troubles."
 * There was also the laundromat-set West Side Story parody "Wash/Dry Story".
 * Hey Arnold had "What's Opera, Arnold?," an All Just a Dream rendition of Carmen with the kids from the show.
 * Bugs Bunny had a few based on classical music, including "Rabbit of Seville" and "What's Opera Doc".
 * Dexters Laboratory had its oft-quoted even to this day LA Bretto episode, which presents itself as an origin story chronicling Dexter's rise from birth to building his secret lab.

"Nothing! Nothing! You only see air!"

"Don't be silly, I love you very much!"

(smash!) "I guess I shouldn't touch.""

""Oo-oo-oo-oo-oo, what does this button do?"

"Oo-oo-oo-oo-oo, what does this button do?"

(pushes Dexter's belly button. Dexter cries.)

"Now I know that this button does: it make my brother cry.""


 * Cow and Chicken has one episode devoted to the school staging Cow's bizarre allegorical musical, "The Ugliest Weenie".
 * Clone High had "Raisin the Stakes: A Rock Opera in Three Parts".
 * Total Drama World Tour is a musical season. Oh yeah, and it's required.
 * The Marvelous Misadventures of Flapjack has All Hands on Deck
 * In one episode of Animalia a core spore blows and all the animals start singing everything they say.
 * In one episode of Curious George called "Sock Opera Monkey", George does a puppet show of the opera Hansel and Gretel to a recording of the music. In another, "Go West, Young Monkey", although he doesn't sing, several other characters do. (Most of this is a dream sequence.)
 * American Dad has Hot Water, a parody of Little Shop of Horrors featuring Cee Lo Green as a sentient hot tub
 * The Emperors New School: The Musical speaks for itself, really. Bonus for being a parody of High School Musical.
 * "Bad Rap" from The Super Mario Bros Super Show.
 * Space Ghost Coast to Coast had "Boatshow".
 * "Veggie Tales" had "Lyle The Kindly Viking".
 * The direct-to-video feature Scooby Doo: Music Of The Vampire is essentially a musical as the Scooby gang and the feature's incidental character break out singing throughout.