The Fall Homecoming at the Museum of Appalachia is a really fine event and if you're looking to learn a little history as well, a great place to go(ANYTIME!). I agree with Arkie above on both he mentions as a matter of fact. Also in August there is an annual event at the Carter Family Fold in Hiltons, Virginia not far from Bristol.

In eastern Kentucky find both Berea College and the Hindman Settlement School then google up info. Do the same for Boon, NC, Elkins W. VA, and Asheville, NC as well. That tristate area enclosed by Lexington, Ky., Knowville, Tn and points east is full of good events but some come and go or change names. A great family band fest has passed on now but I'm sure other new events are coming along too. Sadly at times the newer ones are a bit on the artsy-fartsy side but............

Good Luck!

Spaw