sentences:  From 1966 to 1969, he worked for the government and studied for a PhD.During this time his first marriage had broken up and he had returned to playing music, initially playing the organ in a pub, then playing traditional German music.In 1969, he was invited by Robin Trower to replace Matthew Fisher on organ and David Knights on bass in Procol Harum (at which point that band consisted entirely of ex-The Paramounts musicians).