I was just thinking I needed to learn a couple new fiddle tunes. Those two that Retro Hound suggested sound like good ones. Many of the bluegrass fiddle tunes are written around the main chord shape in the song's key. For instance in "Billy", the C chord in open position, and in "Red Haired", it is the G chord, both in open position. So when it comes time for improvising off the main melody, those chord tones are the keys to sounding good. Good practice for note selection.