I saw JT at Hammersmith Odeon about 20 years ago with ex Fairport Dave (?) Pegg on bass. Great band, and as you say, great musicians playing complicated music so effortlessly that it does not sound complicated. I never did see Yes live, I think their best albums are The Yes Album, Fragile and Close to the Edge. Later stuff was less fresh, and when Alan White took over from Bruford as tub thumper they were past it, for me. By any standards White is a fantastic drummer, but much more rigid and solid, and I always like the way Bruford LIMITED his technical mastery to suit Yes, but still ran circles around some very complex music. "Rubber Wrists Bruford" !