Well Snuffy I would say some people have always been paid to sing folksongs(or play folk tunes) ever since the day after the day they invented money. I do believe there is a radical difference between folk music and other kinds of music, but the difference does not lie in whether the performer is paid on not. In my opinion, of course. But I really don't see how the music of the fiddler in the pub changes just because the landlord slips him a pint or a fiver.I like the other aspects of your definition.