In his autobiography, cellist Gregor Piatigorsky tells about a time he was soloist at a concert conducted by Arturo Toscanini: “The maestro paced the dressing room in which I practiced, repeating, ‘You are no good; I am no good.’ ‘Please, Maestro,’ I begged, ‘I will be a complete wreck.’ Then, as we walked on stage, he said, ‘We are no good, but the others are worse. Come on, caro, let’s go.’ ”…