On myspace, M.Ted, we categorise ourselves into 3 - I put "Folk," "Christian" (because I DON'T see my singing and playing with just the top-lines of my selection of hymns as folk music), and "Other" (as I've tried poetry, also). And I'd agree with those who say folk music can be divided into two distinct categories of it's own - Contemporary Folk (known composer), Traditional Folk (unknown composer).
To DS - I wonder if you'll start singing a folk song to the rhythm of your knitting?