I would not doubt that "Old Blue" has been recorded a hundred times!! Why must a wonderful song like that be connected with any one artist? I just added one more item to my list of "things that make it **folk** music"

"It 'tends' to be folk if the artist is less important than the song"

(yes, I am aware that sometimes you want to recapture some particular version that moved you...out of dozens you have heard...still.. ;-)..)