I'd just like to say that John Davis actually is somewhat of a master of percussive audible nonsense, and I'm not a hater of nu metal, so feel free to submit Korn.
Seriously... Korn is awesome. And as a hobby vocalist John Davis is definitely one of my inspirations. He might not be a falsetto master like so many folks associate with amazing pipes but he's creative on a whole different level. The guy SCATS, for fuck's sake.