Glee is a lot of things, but "especially creative when it comes to its arrangements" isn't one of them. After basically lifting Pedra Haden’s cover of Journey’s “Don’t Stop Believin'” for its 2009 premiere, the show’s gone to the pilfering-from-indie-artists well again. On an upcoming episode, characters sing a smoothed-out version of Sir Mix-A-Lot’s classic “Baby Got Back”—a version that is, nearly note-for-note, the exact same arrangement that Jonathan Coulton released back in 2005.
As one might expect, Coulton’s not exactly stoked about it. He says the show never even contacted him, and even tweeted that he’s pretty sure Glee actually used parts of his original recording (though he’s still looking for audio experts to prove that assertion). So far, there’s been no comment from Glee’s producers, but the evidence is pretty damning. Compare for yourself: