[[quoteright:330:[[VideoGame/SpyFox http://static.tvtropes.org/pmwiki/pub/images/spyfoxmusicswap_3648.png]]]]
[[caption-width-right:330:Swapping sheet music is a common variant.]]

->''"Okay. The game is Cue Card Rummy. I deal."''
-->-- '''ComicStrip/{{Garfield}}''', preparing to invoke this trope in ''WesternAnimation/GarfieldAndFriends'' (episode: ''Health Feud'')

A Script Swap occurs when either [[UnfortunateItemSwap by accident]] or by external mischief, someone winds up reading or following a different document than what they're supposed to, and does so without at any point noticing the mixup.

Setting one of these up is a common AdventureGame-exclusive StockPuzzle. The structure is simple: you've got a character in the middle of reading a speech[=/=]playing a song[=/=]giving someone instructions. Your life would be a whole lot easier if that speech[=/=]song[=/=]set of instructions was different. So you [[LookBehindYou inform the character of the three-headed monkey sneaking up behind them]], then swap their speech[=/=]lyrics sheet[=/=]instructions booklet with another one you acquired [[NoodleIncident by irrelevant means.]]

A common trick to pull on the CartoonConductor. See also OhWaitThisIsMyGroceryList. The cases in which it happens by accident rather than deliberate trickery also fall under UnfortunateItemSwap. Compare the BavarianFireDrill.

* One commercial for Snickers has the news anchors on a news broadcast saying only "AAAAAAAA" because the teleprompter operator had fallen asleep on the keyboard due to hunger.

[[AC:{{Anime}} and {{Manga}}]]
* Variant: In the manga ''Manga/CatStreet'', Keito's script is wrongly transcribed for her by rival auditionees in order to improve their own chances of being selected. Keito cannot read kanji and asked them for help, resulting in a completely nonsensical monologue.
* In ''Anime/SengokuOtome'', when the girls put on a play, [[BitchInSheepsClothing Ieyasu]] changes Nobunaga's script so she will assault the others, ''during an orgy scene''. Nobunaga notices that script seems different, but shrugs it off. Before Ieyasu's plan can succeed, the stage catches fire, forcing everybody to run.

* A slightly inventive version is performed with two typewriters in a ''ComicStrip/SpyVsSpy'' comic.
* ''{{ComicBook/Foxtrot}}'':
** One strip has Paige making cookies while reading the instructions aloud ("Two cups sugar..."), then turning the page ("Chopped onions...").
--> '''Andy:''' I've never liked this cookbook. The pages always stick together.
** Another has Jason hack a teleprompter so it insults his sister, among other things.
--> '''Jason:''' Wolf Blitzer's about to say "Fear me" in Klingon.

* In ''Film/ANightAtTheOpera'', Chico and Harpo swap the sheet music of an entire orchestra so that they all start playing "Take Me Out to the Ball Game" in the middle of the opera.
* ''Film/AnchormanTheLegendOfRonBurgundy'': Ron is noted to be especially vulnerable to this trope, as he'll read ''anything'' written for him on the teleprompter verbatim. Veronica takes advantage of this at the height of their feud and switches out his usual signoff catchphrase for "Go fuck yourself, San Diego!" Ron reads it without missing a beat, then obliviously wonders why everyone in the newsroom is freaking out.
* In ''Film/TheSeduction'', Morgan Fairchild plays a news anchorwoman named Jamie who is being [[StalkerWithACrush stalked]]. At one point the stalker gets into the newsroom and replaces her teleprompter feed. She starts to read it in her bland newswoman's voice until she realizes what she's saying.
-->"Jamie, I'm watching you… "''breaks down on live TV'' He's gonna kill me… Please help me… Please!
* In ''Film/ScaryMovie3'', there's a scene in which two characters type conflicting information into a teleprompter, followed by a technician typing in rude words just for laughs. The newscaster reads it all (including gibberish such as the output from just sitting on the keyboard) with a completely straight face.
* Invoked in ''Film/BruceAlmighty'', with Bruce making another newscaster go completely offscript, the writing staff desperately trying to get him back on track.

[[AC: LiveActionTV]]
* On ''Series/TheWestWing'', President Bartlett is forced to nominate complete non-entity "Bingo Bob" as a replacement V.P. to avoid a long confirmation battle, and his speech writers complain bitterly, going so far as to pen a resounding denunciation of this ridiculous lobbyist lapdog. [[HilarityEnsues Inevitably]], it ends up on the president's teleprompter by mistake. In a partial aversion, Bartlett merely gives a surprised blink and then improvises a glowing eulogy, because he is just that awesome. (And the V.P. actually requests a copy, saying he needs to be aware of what people are thinking of him.)
* In ''{{Series/Seinfeld}}'', when Jerry and George got their mentoring notes mixed up, Bania ends up doing a brilliant stand-up routine about corporate risk management, and George gives a lecture to his colleagues about Ovaltine.
* A classic accidental example from ''{{Series/Friends}}'': Rachel is making English trifle for dessert, but two pages on the recipe book stick together, so she ends up making a mincemeat trifle that [[ItTastesLikeFeet tastes like feet]].
* In one episode of ''Series/StarTrekTheNextGeneration'', a computer glitch replaces the text of a play with some of [[spoiler:Data]]'s poetry. Fortunately, they notice this during rehearsal.
* Done in an episode of ''Series/MurderSheWrote'' with an aging actor whose memory is so bad he has to rely on the teleprompter. While this looks like an EngineeredPublicConfession, it is actually a ploy on Jessica Fletcher's part to trick the real killer into exposing themselves.
* ''Series/JustShootMe'':
** In the first episode, Maya is fired from her job in a newscast for changing the teleprompter on an obnoxious anchor, making her say that she got her frontal lobe removed and that she wet herself.
** Another episode has Nina and Maya nominated for fashion magazine awards. Maya's nomination was for an article that was changed without her permission, so she planned a speech rejecting the award and badmouthing the article. Unfortunately, Nina took Maya's acceptance speech by mistake, causing her to unintentionally decline her reward and making Maya look bad when she won her award immediately afterwards.

* Victor Borge, Danish comedian, conductor and pianist, would switch around ''his own'' sheet music during his comedy act.
* In ''{{Hamlet}}'', Hamlet replaces Rosencrantz's and Guildenstern's letters to the King of England, which originally requested that the king execute Hamlet, with letters that order the execution of Rosencrantz and Guildenstern instead.

* Creator/TelltaleGames loves this trope.
** Episode 102 of ''VideoGame/SamAndMaxFreelancePolice'' does this when swapping a set of game show question cards with an easier set of questions. Possibly justified in that since Hugh Bliss isn't the normal host, he probably has no idea what the questions are supposed to be.
*** Episode 104 of the same series does the same thing with a series of cue cards for UsefulNotes/AbrahamLincoln's statements on the issues. Abe must ''really'' not be paying attention, since the poster and the sign used for the swaps look nothing like the normal cue cards in terms of font and layout... maybe this one relies on RuleOfFunny.
*** Episode 205 has a grocery list swapped with a list of swear words. To be fair, both of them ''are'' written on official stationery.
** The third game of ''VideoGame/StrongBadsCoolGameForAttractivePeople'' has this done with a series of records for the Two-O Duo's dance routines, including introducing two new ones, combining this trope with ProgrammingGame. Coach Z is smart enough not to dance off the stage if that's what the music suggests, but he's not smart enough not to [[spoiler:air-punch his partner square in the face]].
** This is done on two levels in the second episode of ''VideoGame/BackToTheFutureTheGame'', where Marty has to swap the sheet music at the piano so Cue Ball plays just the right music to change the mood so a drunken officer will get in the mood to talk to him. Then when he needs a more inspirational song than the club has to offer, Marty gets the lyrics to such a song, swaps them for Trixie's lyrics to her own song, then changes the piano music so Trixie's song is played. Possibly justified in the latter case in that the two songs have ''really'' similar lyrics, and Trixie explicitly hasn't memorized hers.
* The image is from the first ''VideoGame/SpyFox'' game, where the player has to do this to get tango music playing so Russian Blue will dance.
* In one of the ''{{VideoGame/Reincarnation}}'' games, you change the price of drinks on a bar blackboard so the bartender will serve drinks or not... note that the bartender appears to be the ''only one working the bar'', and yet fails to question the price magically (literally) changing.
* Sims in Politics in ''VideoGame/TheSims2'' can sometimes receive a chance card that says their speech was replaced with the text of ''Titus Andronicus''. A failure to deliver a new speech would get the Sim fired.

* Imps do this to Garland early in ''Webcomic/EightBitTheater''. Garland does notice that the speech written for him by Princess Sara has been replaced by an insult letter, but that still means he has to think up something quickly, resulting in his {{meme}}tic line.
** And the speech is switched back when Garland [[ItWasHereISwear tries to present it as evidence that it has been tampered with]].

* ''WebAnimation/HomestarRunner'': In the WebAnimation/StrongBadEmail [[http://www.homestarrunner.com/sbemail195.html "love poems"]], Homestar produces an acrostic poem that spells out the name of his girlfriend Marzipan. The poem consists entirely of food items.
-->'''Strong Bad:''' That's not a love poem! ''[[OhWaitThisIsMyGroceryList That]]'' [[OhWaitThisIsMyGroceryList is a lavishly produced grocery list]].\\
'''Homestar:''' No, ''here's'' my grocery list! [[TropeName "Amazing thing, amazing thing, amazing thing, amazing thing."]]\\
'''Strong Bad:''' Woah, where have you been shopping?\\
'''Homestar:''' Skymall.

* This is a favorite trick of {{ComicStrip/Garfield}} in [[WesternAnimation/GarfieldAndFriends his animated TV series]]. He's done it with the cue cards for an exercise show (page quote), a disc jockey's advertisement, and a list of pet tricks for a cat show.
* In ''WesternAnimation/TheSimpsons'' episode "Bart Sells His Soul", Bart replaces the hymn sheets and music at the local church with those of Music/IronButterfly's "In-A-Gadda-Da-Vida", labelled as being titled "In the Garden of Eden" by "I. Ron Butterfly". When Reverend Lovejoy picks up on the swap (nearing the end of the entire ''17 minute-long'' song), he remarks that it "sounds like rock and/or roll."
* In ''WesternAnimation/SouthPark'' the gang replace the score for a charity concert with one containing the {{brown note}} so that it will be heard around the world
* In ''WesternAnimation/TinyToonAdventures'', Buster switches the lyrics on a bossy kid's performer so that his song about a monkey who looks both ways to cross the street ends with the monkey being run over.
* In the ''WesternAnimation/TomAndJerry'' short "Carmen Get It!", Jerry pulls a variation of this trick on Tom by having a sizable number of ants rearrange themselves on the conductor's lectern, making him play random songs like "Yankee Doodle", "I Wish I Was in Dixie", and "There'll Be A Hot Time in the Old Town Tonight".
* [[TheBully Roger]] would often do this to WesternAnimation/{{Doug}} such as the time where it led Doug to report that Mr. Bone wore pink underwear. Doug never caught on [[http://dougfunniesjournal.tumblr.com/post/241021275/introducing-doug-funnie because he's crazy]].
* ''WesternAnimation/TheJetsons''
** A TV movie has the encrypted directions to a WMD switched with Judy Jetsons's lyrics submission to pop star Jet Screamer. Screamer likes the directions, mistaking them for song lyrics, and calls it "Gleep Glorp." "Gleep Glorp" subsequently becomes a hit song while the goons tasked with finding the WMD somehow manage to decrypt Judy's lyrics, which lead to a pair of fuzzy dice.
** In the cartoon, a similar plot happens when Judy enters a song writing contest to win a date with Jet Screamer, with George intentionally replacing her entry with Elroy's secret code message in order to sabotage her. This turns out to be a SpringtimeForHitler as the code message, "Eeep, Opp, Ork, Ahah", causes Judy to win.
* In one episode of ''WesternAnimation/AmericanDad'', the CIA holds a telethon to raise funding in order to keep their torture program. Roger, who came up with the idea, becomes enraged by Stan who takes credit for it, and vows to get revenge by sabotaging the telethon. One of the tricks he pulls is messing with the teleprompter so that instead of making the joke "CIA stands for Central ''Insanity'' Agency", Stan ends up saying "Stan Smith was born with both male and female genitalia".
* In the second ''WesternAnimation/GeraldMcBoingBoing'' cartoon "Gerald [=McBoing-Boing=]'s Symphony", Gerald is asked to stand in for an orchestra for the premiere of a new symphony. Unfortunately, some of the pages from his sound effects script get mixed in with the score, and so the music is often interrupted by sound effects. At first Gerald is fired for his mistake, until messages come pouring in praising this new piece of "avant-guard" music.
* In the WesternAnimation/ChillyWilly cartoon "The Legend of Rockabye Point", Chilly puts a clarinet on the sleeping guard dog's mouth, causing it to make noise as he snores and waking him up. The polar bear gets him back to sleep by pulling out the sheet music for "Rock-a-Bye, Baby" and playing it on the clarinet. Chilly then switches the sheet with one for circus music, waking the dog up again.
* Subverted in ''WesternAnimation/ParaNorman''. The ghost of the witch haunting the town wakes up and wreaks havoc because when Norman did the ritual to keep her asleep, he took the book of fairy tales instead of the spellbook. [[spoiler:Then it's revealed that it ''was'' the right book. The witch was only eleven when she died, and her family kept her soul at peace by reading her stories at her grave. Norman messed up because he was at the wrong grave.]]

* Austrian comedy group "Die Hektiker" had a series of sketches about this trope, where a group of criminals swapped out the prepared speeches of high officials. The Austrian defense minister's speech before the NATO becomes the lyrics of "Jingle Bells", the US president's German speech before his Austrian guests a series of insults, and the Pope's German mass becomes the parable of "Jesus and the Self-Cleaning Oven".