Initially writing theatrical scores similar to Kaprow's earliest Happenings, Brecht grew increasingly dissatisfied with the didactic nature of these performances. After performing in one such piece, Cage quipped that he'd "never felt so controlled before." prompting Brecht to pare the scores down to haiku-like statements, leaving space for radically different interpretations each time the piece was performed. Brecht would later refer to Cage as his 'liberator', whilst, in the opinion of some critics, moving beyond Cage's notion of music; Cage was still writing scores to be performed. Brecht had replaced this with a world permeated with music. "No matter what you do," he said, "you're always hearing something."