I'm with Pete Summers, above. The only USEFUL definition of folk music that I've ever heard, is; music originally composed and played by non-professionals for their own and others' enjoyment. Once it's created by pros for performance to an audience that pays - it's not folk music.
But since the rest of the world doesn't all share my take on this, I just have to get by with folks calling James Taylor and Bill Monroe etc, folk music.
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