Piper performs Catalysis series. Conducts a series of juice fasts. Begins CCNY full-time with plans to major in philosophy, musicology, physics, and history; eventually settles for a major in philosophy and minor in Medieval and Renaissance musicology. Clerk in CCNY music library (through 1971). Listens to Ockeghem. Exhibits Context #7 in Information show at the Museum of Modern Art. Withdraws Hypothesis from Conceptual Art and Conceptual Aspects show at the New York Cultural Center, in protest against Nixon's invasion of Cambodia and Kent State and Jackson State massacres. Joins Art Worker's Coalition. Attends open rehearsals held by Steve Reich and Phillip Glass.