He was with the Jerry Garcia Band from 1983 until January 1994, when he was suddenly dismissed for reasons still unknown to him.[3] He went on to spend five years as Bob Dylan's drummer. Kemper joined Dutch progressive rock band Focus from 1975 to 1977, playing both on the Mother Focus album and tour. He has played with Mike Stinson, Elkie Brooks, Dennis Wilson (on the Bambu sessions) and Bernie Leadon. He played double drums with Jim Gordon on Barry McGuire's "Don't Blame God" from his Lighten Up album in 1974. Also played on Joan Armatrading's 1977 album, "Show Some Emotion".[4]