I've been singin' "51 Highway Blues" for longer than I can remember. I first heard it performed by my friend Robert Oneman Johnson. He credits it to Big Joe Williams. I was fortunate to catch a series of film shorts some years back at the Folklife festival. The films were of various artists and their versions of this song. Needless to say my version is very different as well and continues its metamorpose. Such is the folk process.