Cage's tutelage under Arnold Schoenberg left him with a lifelong preoccupation with the relationship between imposed structure and the flow of time. Schoenberg's idea of repetition as a form of variation was a favorite topic in Cage's recorded conversations. He was interested in how musical structure could 'play' time: "As long as structure and method exist by referring back to the mental, to intelligence, time is possessed."a
Cage used chance to minimize the 'mental' in his music. By removing structure, he sought to liberate time, which he considered to be "the radical dimension of all music"b.