For the record, I believe Bob plays the guitar (or one of the guitars, in cases where there are one or more backing musicians) on all his recordings. He has never been a hotshot "lead" guitarist, but he became a very good acoustic-guitar self-accompanyist very early on, well before his "discovery" and the recording of his first album.

In the Scorcese documentary, there's an interview with Tony Glover, who recalls being astounded by the great and sudden improvement in Bob's playing over the short period of time between his move to New York and his first visit back to Dinkytown, Minneapolis. ("It was as though he had sold his soul at the crossroads, like Robert Johnson," or words to that effect.)

(I also, by the way, believe that William Shakespeare wrote all those plays and sonnets...)