Pickleback

 Pickleback was a band that made their first appearence in the episode of the same name. Pickleback is a music group of pickles who sing the worst songs. However, they use their songs to get other fruits and vegitables brainwashed into enjoying their music... until they get pickled. Their main objective was to pickle all other fruits and vegetables because they're sick of being discriminated against because people consider cucumbers the only thing to pickle (in their opinion, anything can be pickled). Eventually, Orange makes "The Most Annoying Sound In The World" (previously used in Sandy Claus) to collapse the stage, thus killing the first and second guitar player along with their drummer, leaving the lead singer, Chad, to get knifed.

Trivia

 * Their band is a spoof of Nickelback, who's music, coincidentally, is considered very bad, like that of Pickleback.