The 79-year-old dancer Yvonne Rainer’s long career has revolved around “radical juxtaposition,” a concept from Susan Sontag. Formally trained as a dancer, Rainer began in the late ’60s to add avant-garde elements of filmmaking, still images, and speech to her art, concocting an endlessly surprising mix of somber and playful pieces. She eventually devoted herself to filmmaking full time and only returned to dance in 2000. In her new works “Assisted Living: Good Sports 2” and “Assisted Living: Do You Have Any Money?” Rainer brings her photographer’s eye to the possibilities of her original medium, loading up her dances with narrative in the form of monologue and jump-cuts in the form of tonal juxtapositions. Both pieces use the same dancers, and while “Good Sports 2” is inspired by sports photos from the New York Times, “Do You Have Any Money?” mostly mines material from old Laurel & Hardy routines. Executed with athletic precision but milked for laughs through pratfalls, Ranier’s pieces crack the pristine shell of traditional dance. Yvonne Rainer performs Friday and Saturday at 8 p.m. at American Dance Institute, 1570 East Jefferson St., Rockville. $15–$30. (301) 984-3003. americandance.org.