Paranoid Bluegrass
You find the darndest things on the Interwebs. Today I stumbled across a link to a bluegrass version of Black Sabbath's Paranoid. And no, I wasn't looking - just because you can't see them doesn't mean they're not after you.
Sure enough there's a bluegrass band called Iron Horse and they have a collection of of Ozzie Osbourne covers called, you guessed it, Black and Bluegrass.
More Iron Horse at YouTube.
These guys play pretty darn good and have great harmonies. They have covered Iron Maiden, Modest Mouse, Led Zeppelin among others.
They even do Hank Williams Gospel! What's not to like?