An 11-piece Open Music ensemble presents two great works from the wilder side of American minimalism. Robert Ashley’s Perfect Lives is a 7-part opera written for television that first aired on public TV in the late 70s and early 80s. Open Music will perform their own arrangement of the first episode, “The Park,” which meditates on hotel rooms, piano lessons, prunes, machines, and time. Julius Eastman’s Stay On It revolves around a sunnily rhythmic theme, which is repeated, stretched, and interrupted until it comes undone. No less profound for all their boisterousness, these pieces occupy a special place in the world of visionary American music.