Krystian Zimerman, the great Polish concert pianist, is usually a man of few words. He doesn't, as a rule, talk to the audience during performances. He says little or nothing in the press between his all-too-rare concert tours - not even about his habit of travelling everywhere with his own Steinway grand piano. He rarely grants them the pleasure of an encore. So he triggered more than the usual rumble of discomfort when he raised his voice in the closing stages of a recital at Los Angeles' Disney Hall on Sunday night and announced he would no longer perform in...