His name is Jonathan Coulton. He is singer/songwriter and a really funny guy. The January 24th episode of Glee - Sadie Hawkins - used an almost note-for-note copy of Coulton's version of Sir Mix-a-Lot's Baby Got Back. Don't believe the Glee hype. Coulton brought this to FOX-TV's attention they didn't care.

SO, Coulton released what he calls a cover of Glee's cover of his cover of "Baby Got Back"  and is donating the sales through February to charity.

The original

The ripoff (alleged)