Leon Bibb was probably the first "folksinger" I ever heard, live. I heard him in Madison, Wisconsin, probably in the late 50's, accompanied from what I remember by Marshal Brinkman. Also, from rather dim memory, I seem to recall that he had been in a broadway musical. I bought an album of his back then, long since left behind somewhere. I think the comparison to Belfonte was understandable because both of them were singers, who sang folk songs, among other kinds of music.
Jerry