Did you listen to the arrangements? I'm seriously asking, I'm not trying to sound accusatory. I just can't fathom how anyone could claim that (A) Coulton's arrangement isn't distinct enough from Mix-A-Lot's original to be considered its own derivative work, and (B) Glee's cover doesn't owe as much to Coulton's…

I don't think that's true, but even if it is, it still seems they used not only his arrangement, but his recording. Shouldn't he get credit/compensation for that?

He has way more original songs than cover songs, many of which are far more popular than his cover songs. I'm not sure what your point here is.

Difference is, Coulton paid the proper licenses to do his cover of Baby Got Back, despite writing completely new music for it.