Gordon Parks’s 1976 film, his last Hollywood feature, is an unfortunately dry and pious telling of the life of the great blues singer. Roger E. Mosley, as Leadbelly, does a lot of fighting, drinking, and singing, but the film comes to an end just as it threatens to leave the cliches behind and get interesting—with the beginning of Leadbelly’s concert career and the gradual co-opting of his music.