In March 1962 the choreographer and dancer Trisha Brown debuted Trillium, her first original performance, at the Maidman Playhouse in New York City. In the three-minute work, she attempted to sit, stand, and lie down in quick, unpredictable succession. With enough repetition and acceleration, she recalled, she’d reach a point where “lying down was done in the air.” Brown’s repertory of more than a hundred pieces, composed over fifty years, comes together in such moments of balanced precarity.