When it boils down to it, it's Sir Mix-A-Lot's song, Jonathan Coulton paid for the rights to do a cover of it, as did Glee. Glee is within their bounds "legally" to cover Sir Mix-A-Lot's song in the same manner than Jonathan Coulton is, because it's technically Sir Mix-A-Lot's song, not Jonathan Coulton's. But, I'm…