S. F. Sorrow is a concept album by the British rock band Pretty Things, released in 1968. It is considered to be the first full-length rock opera. The album marked a shift from the band's earlier rhythm and blues sound to mainstream psychedelic rock. The band's unstable lineup due to alcohol and drug problems resulted in the loss of their creative drummer Viv Prince. S. F. Sorrow is a must-have for any collector of psychedelic rock music.