Incidentally - in response to the decades old thread - nobody defined folk - it defines itself by its very nature - the clue is oin two wotrds "traditional" - a process that creates and ploriferates folk song; and "folk" - the people who made it and passed it on
Plenty of books on the subject and enough genuine folk singers on record as having described what we are talking about.
Those who don't know what it is don't want to - nothing much you can do about that
G'night all
Jim