A musician playing back a recorded “take” is in much this position of frank astonishment and threatened disgust. “Did I really do that?” he asks himself until repetition teaches him an outsider’s dispassionate judgement. Occasionally – very occasionally – his performance surpasses his memory of it. One on a transatlantic liner’s public address system I heard the Beethoven Concerto played as I would dearly have loved to have played it, only to discover that the recording was one I had made with Furtwängler in 1947.