Did 'Glee' rip off Jonathan Coulton's cover of 'Baby Got Back'?

If the cover of "Baby Got Back" on last night's "Glee" sounded familiar, you might've heard indie singer Jonathan Coulton's version of it -- because he claims the show ripped him off!

When the "Glee" track surfaced last week, an angry Coulton pointed out the similarities between it and his own cover of the Sir Mix-a-Lot song from his 2005 album, "Thing a Week One." Here's his tweet:

The two versions do sound eerily similar. Watch them below:

"Glee's" cover: 

Coulton's cover:

On his blog, Coulton said he believes "Glee" used at least some portion of his audio. "Not the vocals obviously, but the instruments sound EXTREMELY similar," he writes. "And I could swear I hear the duck quack somewhere in the background there, though it's hard to say if that's just my ears expecting it."

He also asked his fans to perform an audio analysis of both songs; one of them, Paul Lamere, did so on his Music Machinery blog. When he tried to mix the two songs together, Lamere wrote, "At first I thought I had a bug and only one of the two songs was making it into the output." The differences are very subtle, he added.

Colton said Fox got in touch with him -- only to tell him this was their usual policy for covers of covers. He said reps passed along word that "they're within their legal rights to do this, and that I should be happy for the exposure (even though they do not credit me, and have not even publicly acknowledged that it's my version -- so you know, it's kind of SECRET exposure)."

All Colton would've asked for is a small credit. He pointed out the irony that the show celebrates the underdog. "If this were an episode of 'Glee' I would win," he told Wired. "The way they're behaving is so antithetical to the message of their show."