Sorry but would you enjoy this Eye of the Tiger clip performed by the Giant Bomb crew? I know I did. I also remember the Thanksgiving one which was just the guys making turkey noises. I love these clips.
Personally, as a fan of the Gorillaz, I think people would find it weird because of the vocals themselves are being sung by a program. The Gorillaz are voiced by people, just performed by a virtual band. Though you say they have live people but aren't all the songs still played by the Vocaloid program? Correct me if I'm wrong though.
Personally it's not my thing but I can get it, whatever. I'm just saying other people would find that part weird.