No Reprise Please

"Duncan: You said one song per episode!

Chris: Yeah, but this is a reprise! Not a new song!"

- Total Drama World Tour, 'Walk Like An Egyptian Part One'

A character performs a musical number; a little bit later, another character tries to do the same thing, but is informed, "We've already done that song."

A subtrope of Musicalis Interruptus.

""O friends, not these sounds! Instead let us begin to sing more agreeably and more joyfully.""
 * In an episode of The Mighty Boosh, Howard tries to cheer Vince up by performing a song whose message is that "It's what's inside that counts." A few minutes later, Naboo the Enigma and Bollo start to sing the same song, but Howard tells them, "We've already done that one."
 * In an episode of Jeeves and Wooster (and no doubt in the original story), Jeeves manages to scuttle Tuppy Glossop's budding relationship with an opera singer by having her sing "Sonny Boy" in a talent show the haves are putting on for the have-nots -- the trick being he already got other people to sing it earlier (without Tuppy's knowledge). When she sang she got roundly booed.
 * It was at least four times. The plot was to have Bertie perform it before Tuppy, so Tuppy would be booed and the singer would be unimpressed. It had been performed multiple times before Bertie did so, unfortunately the opera singer was running late and didn't see Tuppy's humiliation. Then to put the plan back on track, Jeeves "passed on a request" from Tuppy that his opera singer love should sing it when she arrived. The audience threw cabbages and she got mad.
 * This is a plot point near the end of A Mighty Wind, as the Folksmen realize that the New Main Street Singers are singing a cover of the song with which they [the Folksmen] intended to open.
 * In Stan Freberg's Lawrence Welk parody "Wun'erful, Wun'erful," after the applause for the Lemmon Sisters' rendition of "Thank You for All Those Cards and Letters, You Folks Out There in Television Land Lant," the next singer, "that man with the deep, deep voice, Larry Looper," offers to perform the same song. Welk (or Freberg's impersonation of him) objects, "I'm sorry, that number has been taken."
 * In the Cole Porter musical Anything Goes, Moonface Martin sings "Be Like the Bluebird" in an attempt to cheer up Billy after they're left to rot in the brig. When two more characters are thrown in with them, he starts to sing the same song, to which Billy responds "Would you forget about that?!"
 * In the film version of Little Shop of Horrors, Seymour and Audrey are about to go into a reprise of "Suddenly Seymour" right before the climax of the film when a Traveling Salesman cuts them off. "If you two lovebirds would stop singing for just one minute..."
 * The opening section of the finale of Beethoven's Ninth Symphony, after two hectic outbursts, proceeds to a lengthy instrumental recitative, with snippets from the three earlier movements which every time are inconclusively cut off. Though the meaning of these interruptions cannot be precisely explained, after a four bar passage not borrowed from a previous movement but hinting at the real theme of the finale, the instrumental recitative proceeds quickly to a triumphant cadence, followed by an extensive development of the theme. Between this development and the actual singing of Schiller's "Ode to Joy" to this theme, the music returns to the hectic outburst that opened the movement, and a shorter version of the recitative, this time actually sung, with words which may be taken as explanation for the earlier interruptions:


 * Played with in The Muppets when the opening song is reprised at the end. The villain angrily says "will you people stop singing? You've already done this song!" Except he says this as part of the song itself. And the singers ignore him and go on with the song anyway.