I was thinking about Sean Lennon and Mick's daughter...
Yeah, when Lennon was alive, they colaborated a lot. In fact, the Beatles were good friends with the Stones.
One of my favs is John singing "Yer Blues" at the Rolling Stones Circus show. http://www.youtube.com/watch?v=LAjdRHzH4M8
Barcelona, October 22nd 2008