.. Gould's memory capacity was legendary. Both his mental and finger memory made it possible for him to reproduce and play music literature many years after his last practice and performance of the same. A famous illustration of this statement would be an event that occurred in 1970, when the renown Italian pianist, Arturo Benedetti Michelangeli, was unable to go through with his performance of Beethoven's Concerto No.5, Emperor, in Toronto. Gould was given a telephone call on Thursday evening. The problem was explained, and he was asked to substitute for Michelangeli the next morning, on Friday, when the Toronto Symphony and the conductor, Karel Ancerl, were scheduled to work with Michelangeli. Gould's answer was affirmative and good-spirited. In the space of the next few night hours, Gould rehearsed the Concerto he had not touched in four years. The program was televised and, subsequently, aired on September 12, 1970. To everyone's amazement, Gould played Beethoven's Concerto in front of the camera flawlessly and by heart.