''The Sing-Off'' is an American [[RealityTV television]] [[ExactlyWhatItSaysOnTheTin singing competition]] featuring ''ACappella'' groups. It premiered on Creator/{{NBC}} on December 14, 2009, and was cancelled for a couple years after its third season.

''ACappella'' groups are chosen by audition and advanced in the competition based on judges' eliminations until the finale, where the winners are determined by viewer votes. The winning group receives a cash prize and a Sony Music recording contract.

Unlike many other music-based TV competitions, auditions aren't part of the show, so all the groups viewers see are made up of excellent musicians. The entertainment value comes from the music itself rather than schadenfreude over poor performers. The judges (especially Music/BenFolds) often offer [[ShownTheirWork in-depth musical critiques]], making the show a treat for knowledgeable musicians as well as general fans.

It's hosted by Nick Lachey (formerly of the BoyBand 98 Degrees); with judges Music/BenFolds, Shawn Stockman (of the R&B vocal group Boyz II Men), and various women in the third seat: [[Music/PussyCatDolls Nicole Scherzinger]] in Season 1, SaraBareilles in the second and third seasons, and now {{Music/Jewel}} in Season 4.

Its fourth season finally premiered on December 9, 2013.


!This show contains examples of:
* ACappella: The show features only these groups.
* AuthorAppeal: More like Judge Appeal; most of the judges have a background working with ''ACappella'' (Ben produced an album of covers of his songs done by college ''ACappella'' groups, Sara was in a college ''ACappella'' group, and Music/BoyzIIMen still regularly perform songs this way).
* BassoProfundo: Many, but season 3's Avi Kaplan from Music/{{Pentatonix}} and season 4's Tim Foust from Home Free are the most prominent examples.
* BeautyBrainsAndBrawn: Nick describes Jewel, Ben, and Shawn as the beauty, brains, and brawn in season 4. Nicole and Sara could also qualify as the beauty in their respective seasons.
* BrainBleach: In season 3, Shawn says he needs this after the Yellowjackets perform "Wannabe" by Music/SpiceGirls.
* BreakoutCharacter: Season 3 winners Music/{{Pentatonix}} have become very popular in their own right, and are part of the reason why the show eventually did end up being brought back for a fourth season.
* ColorCodedCharacters: The members of each group are given coordinated outfits each week, though they switch it up so as to prevent people from identifying the group with just one particular color. Though groups with colors in their names (e.g Afro-Blue, The Yellowjackets) tend to wear the same color each week.
* CommercialBreakCliffhanger
* ConsolationPrize: Averted in the conventional sense, but while Season 3's finalists sang in the finale with the judges (and Nick Lachey), almost-finalists Afro-Blue got to sing with Smokey Robinson. That's got to count for something.
* CoordinatedClothes: The members of each group are given coordinated outfits each week, though they switch it up so as to prevent people from identifying the group with just one particular color.
* ConstructiveCriticism: The preferred method, by far, for the judges' criticisms.
* TheCoverChangesTheGender: Done whenever applicable.
* CrowdSong: The opening number each week is a number done by all of the groups (in the first part of Season 3, this was changed to all of the groups in that week's bracket).
** Happens literally when Ben Folds and the Dartmouth Aires perform Ben's song "Not the Same" in season 3.
* DoNotGoGentle: The "Swan Song" invokes this trope, particularly when the group being eliminated isn't likely to outlive the show; even though they are already eliminated from the competition, you can still expect a heartfelt performance as they walk off the stage.
* DramaticPause: Go ahead, time Nick when it comes down to seeing which of the bottom two groups is to get eliminated.
* EliminationCatchphrase: Variations on "And now please raise your mics one final time for your Swan Song."
* EliminationStatement: In seasons 1-3, each eliminated group gets to perform a "Swan Song," one last tune as they leave the stage.
* FollowTheLeader: While much different in tone, plus the ''ACappella'' gimmick making it distinct, it's unmistakably following in the mold of ''Series/AmericanIdol''.
** In an in-show example: after Season 4's Home Free made a big impact with their BassoProfundo, Tim Foust, a lot of their competitors started tapping their basses to do similar things.
* FunnyBackgroundEvent: After the first elimination in the first episode of Season 3, while Nick Lachey is introducing the next four musicians, Shawn Stockman and Ben Folds start waving and posing for the camera behind him.
* GenreShift: Can happen during the ultimate sing-offs in season 4, due to the groups singing two halves of the same song, each in their own style. Calle Sol's battle with the [=acoUstiKats=] had the song shift between calypso and pop, and Filharmonics battle with Street Corner Renaissance had the song shift between pop and doo-wop.
* GuiltyPleasure: The theme of a OnceASeason episode, giving the groups a chance to perform some [[NarmCharm slightly embarrassing]] favorites (such as pop hits from TheEighties).
* IncrediblyLamePun: Nick spouts one in his introduction for every performance, normally relating to the song's title. He'll often pull another once the song is done.
* IncrediblyLongNote: Michael from the Dartmouth Aires managed to belt out a high A-flat for so long it messed his own group up. Doubles as a CrowningMomentOfAwesome since this performance was in a [[TitleDrop literal sing-off]] with another group to help the judges decide who got to go to the finals.
* [[ReviewerStockPhrases Judge Stock Phrases]]: "Pitchy," "beatboxing," "you did your thing," and any instance where the singers are described like non-vocal instruments.
* NeoclassicalPunkZydecoRockabilly: This can happen with some of the more exotic groups. Music/{{Pentatonix}} and Urban Method from season 3 were notable examples, with Music/{{Pentatonix}} using electronic influences and Urban Method's "rapapella" style (mixing rapping and ''ACappella'' singing, which worked surprisingly well).
** Season 4 sees the show's first A Capella Country group, Home Free.
* OnceAnEpisode: After about three episodes, you'll know roughly when Nick is going to say "This is a vocal competition using only their voices" and his other stock phrases.
* OnceASeason: Although you can't always exactly predict when, you'll also see Nick bemoan the fact that nobody wants to sing a 98 Degrees song (usually after someone does a song by a different BoyBand).
** Finally {{subverted}} in the finale of season 3, when Nick joined forces with Music/{{Pentatonix}} to perform (you guessed it) a 98 Degrees song, "Una Noche."
* PerfectlyCromulentWord: Ben Folds is probably the worst offender, but all of the judges use words that sound like they're either music industry insider lingo or ones they just made up ("pitchy," borrowed from ''Series/AmericanIdol'', seems to be the most popular).
* PissTakeRap: While remarking on a performance by "rapapella" group Urban Method, Music/BenFolds improvised[[note]]Ben's rap was actually lifted from a song called "Get That Bug Out Of Your System" by his old band Majosha. It showed up again in a song called "For Those of Y'all Who Wear Fanny Packs" on Ben Folds Five's B-sides collection, "Naked Baby Photos."[[/note]] some extremely nerdy freestyle. HilarityEnsued.
* PowerTrio: The judges.
* ProductPlacement: They are not shy about notifying folks as to when any of the judges are about to have another release.
* SesquipedalianLoquaciousness: Music/BenFolds sometimes employs it [[PlayedForLaughs for laughs]]. "Thumbs aloft, gentlemen."
** He even lampshaded it in Season 4: "Are you {{calling me a|logarithm}} sesquipedalian?"
* ShoutOut:
** Any high school group is going to be greeted with some comparison to ''Series/{{Glee}}''.
** In Season 3, Sonos chose Boyz II Men's "It's So Hard To Say Goodbye To Yesterday" as their Swan Song upon elimination. Shawn was visibly embarrassed.
** In Season 3, Michael from the Dartmouth Aires shouted "Sing-Off!" in three of their performances. Four, if you count their [[http://www.youtube.com/watch?v=V8aBj9ThfSA audition video.]]
** The Yellowjackets' Swan Song (from Season 3) has several shout-outs, both to the judges and to the show.
** The Princeton Footnotes paused their performance to sing, "[[AscendedFanboy We love you Ben]]!" during season 4.
* ShownTheirWork: Ben Folds in particular will show off his familiarity with the mechanics and techniques of ''ACappella'' singing, the other judges as well if less frequently.
* TheSixties: The subject of another one of the theme episodes.
* TechnicianVersusPerformer: Some elements of this, particularly with various college groups falling under the "technician" umbrella.
* ThatCameOutWrong: SaraBareilles has a few "why did I just say that" moments in the first episode of Season 3.
-->'''Bareilles''' [''regarding [[spoiler:Afro Blue]]'']: ...and I also wrote down that you're all very attractive, so... [''general laughter''] ...maybe I need to work on taking notes, [[DiggingYourselfDeeper but you're all very good looking in addition to sounding amazing]] -- [''to Ben Folds, leaning over to read her pad''] -- it's on there, it is on there. I know. [[RefugeInAudacity Get over it.]]
* TitleDrop: Season 3 introduced the first official "Sing-Off," in which the two lowest-ranked groups battled each other for elimination, each performing the same song for the judges.
** This becomes the new method of elimination in season 4.
* UnCancelled: After taking a year off, it was brought back for a fourth season in 2013.