Now, I don't know a damn thing about bluegrass festivals, but a capella I do know - 'cause I haven't had the time to learn any of the instruments I WISH I could play, and can't keep from singing in the meantime!I say go for it. And do what Barry said; do what Barry DOES. Sing the song that you sing in the shower, the car, the laundry room. The one that gives YOU goosebumps when you sing it.
Dani