Two conceptual films by the Japanese-born artist. No. 4 (Bottoms) (1966, 80 min.), Ono's first and best-known work featuring the human body, is a montage showing 365 pairs of moving bare buttocks, every shot framed identically and each lasting no more than 15 seconds. The parade gets pretty monotonous by the end, despite Ono's voice-over rhapsodizing on the innocence and vulnerability of her subjects; only the verbal contributions from participants, scandalized critics, and filmmakers explaining the logistics of the project kept me from dozing off. Ono's playfulness is more pronounced in The Museum of Modern Art Show (1971, 7 min.): an interviewer in front of the museum, asking passersby to respond to a Yoko Ono exhibition there, collects opinions about her and avant-garde art, but the joke's on them—there's no exhibition. It's a fun segment, though 30 years later its most radical implication may be that Steve Allen's man-on-the-street segments from the old Tonight Show were conceptual art.