Summon Backup Dancers
Whenever it's time for a musical number, the lead dancer and singer (whether hero or villain) can usually pull any Innocent Bystanders into a Crowd Song, and thanks to Spontaneous Choreography have them all dance and sing in perfect sync.
Some leads can go a step further. Rather than make do with whoever is nearby, or go solo if there's no one else around, they can Summon Backup Dancers from out of sight, bringing a battalion of ballerinas to dance at their side. To make this more impressive, they'll usually be summoned directly from the Universe of Wardrobe and Costuming after having been fitted in perfectly appropriate attire for the song in question.
This trope isn't usually a magical spell that can summon dancers like a wizard can summon monsters (though in a wacky enough series, it may well explicitly be one), more often it's an implicit rule of the cosmos. Anyone who goes into a musical number will get accompaniment, even if it requires the Spontaneous Generation of said dancers from hard vacuum. Other times, it can be humorously Justified by the lead in question training friends, allies or subordinates beforehand and instructing them to hide out of sight and march out on cue for their big song.
If this is a magical ability of some type, the backup dancers may help out by dance battling alongside the summoner.
- Extra ballerinas appear out of nowhere from time to time in Princess Tutu.
- In Scott Pilgrim, Evil Ex #1 Matt Patel can summon Demon Hipster Chicks to help him cast his flaming hand attack. In the videogame, these attack the player.
- In Shrek 2, the Fairy Godmother enchanted Fiona's furniture to sing along with her about giving Fiona a makeover.
- Giselle's Disney-Princess magic in Enchanted turns the jaded denizens of New York into her backup chorus, leaving her stodgy love-interest baffled that everyone seems to know the same song. "I've never heard this song!"
- In The Mask, the titular character does this to a SWAT team.
- Just like in the series, Matthew Patel summons his demon hipster chicks in Scott Pilgrim vs. the World.
- In North during the Texas song a group of back up singers and dancers appear out of nowhere, this is justified It was All Just a Dream.
- In Leprechaun In The Hood the Leprechaun uses his powers to make the people in a night club sing and dance for him.
- Happen's during Janki's Item Number "Badi Mushkil" in Lajja
- Simon Zealotes explicitly does this in the 1973 version of Jesus Christ Superstar.
- Nicely played with in Buffy the Vampire Slayer's Musical Episode, "Once More With Feeling", as Buffy's confronting, via a musical number, the demon responsible for the whole mess...
Giles: She needs backup! Anya, Tara!
(Anya and Tara take backup dancer positions and join in)
- Played straight earlier when Tara is singing her love song to Willow "Under Your Spell". While dancing through the park she passes near two other girls resting by the pond who are compelled to rise to their feet and start dancing behind her.
- Ryutaros from Kamen Rider Den-O not only has a summonable group of breakdancers (one of whom was the Victim of the Week for Ryuta's spotlight arc), but his powers include the ability to make everyone nearby dance along with his theme music.
- In The Movie (the first one), he even summons a kick line of chorus girls.
- A very, very big chunk.
- In the music video of Sara Bareilles' "Gonna Get Over You," she doesn't so much as summon her backup dancers as more infect the shoppers of a Mexican supermarket, turning them into her leather jacket-clad minions.
- Averted in the 1993 Broadway version of Tommy, in accordance with composer Pete Townshend's strict instructions to collaborator Des McAnuff that there be "no fucking dancing."
- Pippin does this most obviously in "Kind of Woman," which brings a bunch of adoring backup singers come to Catherine's side. They disappear when the song is over, leaving her alone with Pippin as before (but not really, since the show has No Fourth Wall).
- Plants vs. Zombies is the Trope Namer. The lead Dancer Zombie does this, summoning four backup dancer zombies.
- In Ratchet and Clank Up Your Arsenal, evil robot pop diva Courtney Gears does this during her boss battle.
- In Guild Wars, the collector edition of the expansion Factions comes with a bonus that, among other things, gives Ritualist and Assassin characters ghostly backup dancers with the /dance command.
- In Dragon Quest IX, the ultimate Luminary skill, Disco Stew has your guy doing a dance routine while a bunch of backup dancers appear behind him/her. Somehow, this does damage.
- A spell in Kingdom of Loathing called "Raise Backup Dancer" lets you raise backup dancers from the dead.
- In The Nightmare Before Christmas: Oogie's Revenge, gaining enough musical notes in a boss battle sends you into a Rhythm Game section. Doing well summons skeletal backup dancers.
- Space Channel 5 has any hostages you rescue join you in dance.
- In most Kirby platformers, Kirby clones himself and performs a Happy Dance.
- World of Warcraft features a quest where Sylvanas gets nostalgic and summons a backup choir of banshees.
- When Edgeworth is introduced in the first Takarazuka musical adaptation of the Ace Attorney series he immediately summons a group of backup dancer clones for his intro song.
- Invoked in Phineas and Ferb, in the song Rubber Bands, Rubber Balls, Baljeet's uncle, Sabu, summons his factory workers as backup dancers.
- Backup dancers sometimes appear if Doofenshirmitz tells Perry this week's Backstory in song; he explicitly hired them at least twice. The trope is sometimes justified only by Rule Of Don't Be So Pedantic, It's A Cartoon, such as when Baljeet sings about his fear a bad grade if he fails to make a portal to Mars - he summons not just backup dancers, but scenery and elephants too!
- An episode of The Boondocks shows us Tom pining over Sara after she throws him out of the house. He then breaks into an Usher-style love song in the middle of the street, complete with back-up dancers who appear to be just neighborhood guys in their robes and pajamas. They perform perfectly until they are almost hit by a car.
- The Music Meister's superpower in Batman the Brave And The Bold is to hypnotize people with this singing. He thus makes backup dancers out of a horde of supervillains and superheroes.