He was a bloody great songwriter before the smack got him by the balls too. By Mck's own admission, Keef used to write nearly all the music in the Stones ... until after "Exile on Main Street", when other members had to take over because the latter was too incapacitated to come up with anything other than the odd half-formed riff. Co-incidentally, the Stones went shite at around the same time. Funny, that.