I agree with the posting above. The Crooked Road is about tourism but I had been traveling that route and discovering the musicians and singers way back before the book and subsequent publicity came about.
I see nothing wrong with encouraging tourism as long as it doesn't go the route of Beale Street, Bourbon and Royal and to a certain extent Nashville's Broadway.
With singers such as Horton Barker, Almeda Riddle, Mary Lomax etc. You seem to be be referring to "Ballad Singers". It is my understanding that this type of material was mainly sung around the confines of home and family in the States whereas in the UK it would also be sung in pubs especially on a Friday or Saturday night and gaining a wider audience before the days of recording. I would assume that there are still quite a number of people that sing the old songs as well as newer ones around home but if no-one seeks them out and records them as Art Rosenbaum has with Mary Lomax then we won't ever hear them.

The term folk has certainly evolved it now seem to mean anyone with an acoustic guitar hanging from him.

Hoot