I loved erica's thoughts about the magick of folk songs. There is a sum to a traditional folk song that is greater than its (definable) parts. While I have to say I'm a traditionalist and agree with Bruce O.'s definition, I do feel there are contemporary writers like Jean Ritchie who are so immersed in traditional music that their composed songs are passing almost seamlessly into the tradition. Here's hoping we all live at least another 50 years, so we can find out!