“Rumstick Road,” from 1977, is a part-documentary, part-vaudeville, part-nightmare in which Gray recounts the mental deterioration and eventual suicide, in 1967, of his mother, Bette. Actors lip-synced to recordings of his family members or ran around like kids; a cool-voiced Spalding showed slides of his childhood home, where his mother lost her mind. Howes — an instinctive dancer and an imposing presence onstage — played an archetypal “Woman” figure. She was simultaneously Bette, and not-Bette, and the Bette that no one knew.