There'll definitely be some Celtic music, and lots of beer, Art! As Don says, it helps to check your program for the official performances (e.g., the Celtic band scramble), but you'll often find it being played spontaneously in the participants' lounge or around the grounds too.
I'll be there, joining in some band scrambles and bluegrass jams, among other things. Gotta find my Mudcat T-shirt. Maybe I should order a spare. Does Mudcat still have 'em for sale?
It'll be good to see some of you folks again - and others for the first time.