He sometimes wore fingerless gloves while he played, sang along with the music, and sat on a stool so low that he could touch the keyboard with his nose. Before a performance of the Brahms D minor piano concerto, Conductor Leonard Bernstein turned to the audience and made a short speech, dissociating himself from his soloist's unorthodox view of the piece. At his Cleveland Orchestra debut in 1957, he tangled with the irascible maestro George Szell over his use of the soft pedal in a Beethoven concerto; Szell never performed with him after that, but saluted: "That nut's a genius."
Wit,...