Photo by Henry Diltz When I listen to a new Paul McCartney song, I find myself searching for signs that the genius is still there. I’m scornful if he uses an obvious chord progression: then I remember he probably invented that particular chord progression sixty years ago. Ringo Starr was never a genius, so as time has gone by, his own solo records have taken on a value proportional to his age, which cannot be said of Paul. Starr’s warm and ploddy voice is, at 85, a piece of living history, and his steady drip-drip of releases – a creative impulse that is never explained, because he doesn’t really give interviews – is a trailing root to the past that we currently take for granted. In the late Fifties, Ringo was the busiest drummer in Liverpool, largely because he owned his own kit.…