I just remembered a comment from Pierre Boulez last month during a rehearsal, perhaps for Petroushka?  There was a thorny spot, and as is his habit, Boulez isolated one voice, the harp.  After a couple of repetitions, Boulez looked perplexed and solfeged the harp notes.  The harp disagreed: "No Maestro, I'm in treble here."  He paused, looked at the orchestra, and with his classic Gallic tones, quipped, "We are all in trouble here."

We had an unusual Saturday noon rehearsal, and our intrepid piano soloist was to be found at the hall as well.  Actually, in a hallway, outside the men's locker room.  There, at the piano, he played the same passage at least 50 times.  What was the passage?  It wasn't from the Brahms.  I found out that night, after the Brahms, during his first encore, the Chopin c-sharp scherzo.  There I heard the passage, twice as fast as I had heard it in the hallway.  I suppose I should be grateful that he doesn't keep it a mystery how he does what he does.

One of our cellists who was around to see it told me about a recording project with Brendel and the five Beethoven concerti.  Brendel practiced every moment that the mics weren't on, and at one point the cellist saw blood on the keys!  We're thinking that in Kissin's case it would have been ice water.