The first section of Lives of Performers, which observes choreographer Yvonne Rainer as she rehearses a group of dancers, seems to be pure documentary. But Rainer soon reveals that there’s nothing pure about her 1972 film debut, which is more concerned with cinematic form than motion or narrative. The director uses various strategies to accentuate the medium’s artifice: filming in grainy black-and-white, shooting long takes of still photographs, and using intertitles and disconnected voiceover. Like Jacques Rivette, Rainer is concerned with theatricality in all its forms, including in real life. (The film’s subtitle is “a melodrama.”) Yet Rainer differs from Rivette in that she doesn’t take her stage play to the street, restricting the entire film to rehearsal halls and theaters. Finally, she presents the underlying tale in 35 simulated stills (actually live shots of motionless actors) set to—hey, it was 1972—the Stones’ “No Expectations.” The film shows at noon at the National Museum of Women in the Arts, 1250 New York Ave. NW. $10 (includes museum admission). (202) 783-5000.