At the symphony, Mitsuko Uchida walked from side stage to the Steinway concert grand, bowed low, sat on the bench and raised her hands to the orchestra. Mitsuko Uchida would both conduct and play Mozart piano concertos. I was mesmerized. At intermission, two men in dark suits went to the piano, inserted a wrench into the workings, tapped a key, turned the wrench, tapped and turned until that one note was perfect. Of the 88 piano keys, one key was out of tune. With a full orchestra playing, I could never hear it, but Mitsuko Uchida did, and played on.