Ginger Baker
I can't say I knew Ginger particular well, but I did listen to him play before he got involved in R&B, when he used to play a lot of modern jazz and things. I saw him and a few other people who turned coats as you might say, becoming an R&B musician from a jazz musician.
There were always stories about him being difficult and, from what I can tell, now he's even more difficult to get on with. I was much closer to Eric Clapton. Cream were getting a tremendous following every time they played then, the crowds went mad!