Though there's a lot to dislike about him (sloppy performances, disdain for the public, uncredited use of traditional melodies) I rate Dylan as well (Though I prefer his pre- "Motorcycle accident" output) as to why he changes his songs, it's many years now since Dylan could have been called a folk singer in any meaningful sense of the term but there are at least 2 things he retains from folk tradition. One is the great emphasis he places on live performance, the other is the approach he takes to recording. Although in rock the released, studio-recorded version of any given song tends to be considered the "definitive" one, in folk a recording of a song is merely a record of what it sounded like that day. This still seems to be Dylan's approach and I respect and admire that.
