On a slight tangent, I'm puzzled by the number of people who come to prominence as good singers of traditional songs, then switch to performing mostly self-written material that often isn't much cop and never record the traditional material that attracted attention in the first place. Is there more money in being a mediocre singer-songwriter than in being a good singer of traditional song? Or is it that they always planned to have careers as singer-songwriters and just used the folk scene as a springboard?