On the Appalachian front, “O Brother Where Art Thou?” would be a starting point – there was a concert of the film music called “Down From the Mountain.”
Other than that, a singer who gives me goose bumps is Iris Dement:
[video]http://www.youtube.com/watch?v=o9-pDSYPrio[/video]
A couple of others:
Laura Cantrell:
[video]http://www.youtube.com/watch?v=ekd9k4zt1B4[/video]
Diana Jones:
[video]http://www.youtube.com/watch?v=tV3G90GL92k[/video]
Catherine Maclellan
[video]http://www.youtube.com/watch?v=ahe3w7B6FtU[/video]
Just so much to choose from.
Edited for equality:
[video]http://www.youtube.com/watch?v=Y4V_G20zdrQ[/video]