Ha, and looks like you posted it on the 8th of January! Awesome. This is pretty close to how Tony Rice plays it, too. Never heard Billy play it. I play it out of open D, and it works out really well -- learned it from Dan Crary. His version has more notes, just steady sixteenths, so it's harder to play real fast. The one you're doing is built for speed -- I need to learn it. : )