Black Sabbath
In 1975, Sabbath released Sabotage, which featured some longer more progressive songs, and had a less doomy sound. This change in sound continued with 1976's Technical Ecstasy, which received mixed reviews. Osbourne lost interest in the band and left for a short time. After that ex-Fleetwood Mac singer Dave Walker was the lead vocalist. Osbourne decided to rejoin in time their eighth album titled Never Say Die!. It got ok reviews.