The King of Mashups is a school teacher named Bill McClintock who posts over on Youtube. I'm going to post here a couple of my favorites. Someone really needs to start playing these mashups out live.

R&B singers never got the respect they were due in the hard rock community. This was an undeniable mistake as the best singer in Ratt turned out to be Marvin Gaye:

And the best singer in Van Halen turned out to be none other than Stevie Wonder:

Note that I was never a fan of either of these two bands, but put them together, and something incredibly hysterical happens: