Manly Wade Wellman wrote about a character "Silver John" who went about banishing evil with his silver-strung guitar in the Ballad of Silver John. We once did this as a musical play. It has lots of Appalachian songs in it.

Also Harold Bell Wright wrote Shepherd of the Hills which is set in the Ozarks and has some hill country music in it.

In the movies "Oh, Brother Where Art thou" and "Cold Mountain" and "Songcatcher" there is lots of traditional music..presumably these are based on books?