He used to appear at the the Cellar Door in D.C. billed as John Hammond Jr., his father being the famous Columbia Records exec who was credited with discovering Billie Holiday, Bob Dylan and Stevie Ray Vaughn, among others.
I chatted with him once at the upstairs bar at Tobacco Road in Miami and was surprised to find him so thoughtful and urbane after seeing him go into beast mode in his first set. When he launched into a song he was like a man possessed.