The piano technician, Franz Mohr, observed:
Horowitz was consistent in all that he did. His rehearsal was always on Saturday at 4:00 p.m., his performance was on Sunday. And I always had plenty of time to prepare his piano for the concert.
Of course Horowitz would have never stolen my preparation time in order to practice. He was. om that sense, very lazy! Over the years Elisabeth and I were always invited to join Horowitz’s birthday parties. October 1 is his birthday. Two years ago that birthday party was in the home of his manager, Peter Gelb, on Riverside Drive. When we arrived, Horowitz was sitting on the couch. It was a black tie affair: everybody there was well dressed (except James Levine, who was dressed as usual in his dark sweatshirt, sneakers, and a towel over his shoulder).
Well, as soon as we came into the room Hortowitz pointed his finger right onto my face, and shouted loud, so that all the people heard it, “I don’t want to see you! You remind me of work! I hate work!”
And, that was the absolutely [sic] truth. I never could tune his piano in his house before 12 noon, or sometimes 12:30, because he would still be in bed. Sometimes he would come down and watch me tune; other times he would come down when I was finished. Then he would have breakfast. I believe he played a few hours after that, and then maybe late at night he played again for an hour or two. But that was the extent of his playing.Franz Mohr (2000) My Life with the Great Pianists: Horowitz, Cliburn, Rubinstein & Others. Grand Rapids: Raven’s Ridge Books, p. 31.