That's quite a statement from a guy known for dressing up in a boiler suit, donning a mask that looks like horror film character Leatherface and bellowing vocals on songs titled "The Heretic Anthem" and "Pulse Of The Maggots."

But the Slipknot and Stone Sour frontman was, for sure, in unusual surroundings Friday, performing Cheap Trick covers, accompanied by Cheap Trick's Rick Nielsen, along with Nirvana alumni Krist Novoselic (bass), Dave Grohl (drums) and Pat Smear (guitar). The show was part of the celebration around the Grohl-directed documentary, Sound City, following its debut at the Sundance Film Festival.