When I was in high school I had a recording of Big Joe Williams (not the jazz singer who played Bill Cosby's father-in-law, but the blues singer) on which he played a 9-string guitar. I had a friend who also had a Big Joe Williams record and I was always jealous since on his record Big Joe had taken the trouble to tune his guitar accurately, but on mine, the guitar was badly out of tune. One of his songs I recall was Baby Please Don't Go.