Chapman was the person through whom Bill Wyman was enlisted to the Stones, having been in Wyman's band The Cliftons. It was Chapman who made enquiries about vacancies with the Stones and discovered they might be found at the Wetherby Arms on the King's Road, Chelsea. He and Wyman turned up for a run-through and although they had doubts about the blues style and did not like the name, agreed to join on a make-or-break basis. Another drummer, Steve Harris, also sat in for some sessions - Charlie Watts was still with Alexis Korner. After a short time Chapman felt he did not fit in with the way-out approach of the group and left to form a band called The Preachers. It was not long after Wyman joined the group that Watts took over the drums.
Chapman's group, The Preachers had a less wild approach. It was one of the first bands of Peter Frampton and was produced and managed by Bill Wyman. Chapman was responsible for the first meeting between Wyman and Frampton. After The Preachers, Chapman went on to play drums in The Herd, where he was a member for the first two years, again with Peter Frampton, and also with Andy Bown (later of Status Quo) and others.