Today, with a recording, he can hear the thing enough times until he really gets acquainted with the language, and then he can begin to make an estimate of the intrinsic, aesthetic value of that piece of music.

Though he gave his last public concert before the age of forty he continued writing music for another half-century and beyond. His performances of works by avant-garde composers and his own innovative and even shocking pieces made him a cause célèbre on both sides of the Atlantic.