I admit to being a casual bluegrass fan. I once wore out a cassette of the greatest hits of Flatt and Scruggs, but I'd have to say "Fox on the Run" is probably my favorite bluegrass song. Here's a version..
If I'm reading the comments correctly the gentleman playing banjo survived an electrocution, which tossed him off a ladder and caused paralysis in his legs. Yet he plays on, captured for posterity on this blog and many others. Bravo. Such represents the true essence of You Tube.