Louisiana bluesman Robert Pete Williams had a unique, haunting style. His verses aren't constructed in the standard AAB format most blues conform to, but are unrhymed, stream-of-consciousness ruminations on the subject of the song. His guitar playing is unpredictable and virtuosic, interacting with and amplifying his lyrics.
Williams was serving time in Angola when he was discovered and recorded by ethnomusicologist Harry Oster. Louisiana Blues dates from 1967, after he had been released from prison. It was released on the John Fahey's Takoma label, which specialized in blues and folk music. Here's a sample of Williams' beautiful music from this album: