Bob Neuwirth

Bob Neuwirth (born June 20, 1939, Akron, Ohio) is an American singer, songwriter, record producer and visual artist. A mainstay of the early 1960s Cambridge, Massachusetts, folk scene, he subsequently became a friend and associate of Bob Dylan alongside whom he appears in D.A. Pennebaker's documentary Dont Look Back and Dylan's own self-referential romantic fantasy/tour film Renaldo and Clara. Neuwirth assembled the backing band for Dylan's 1975 Rolling Thunder Revue. With Janis Joplin and poet Michael McClure, he co-wrote the song "Mercedes Benz". He also introduced Kris Kristofferson to Janis Joplin.

source: Wikipedia