The vocoder was pretty much a space helmet party until Laurie Anderson topped the British charts with this haunted duet with herself and an answering machine in an empty room, foreshadowing incoming planes. On the early, pre-war Bell Labs vocoders, the "frequency discriminator"(their words) had trouble recognizing women's voices. "O Superman's" syncopated holding pattern—a phone off the hook, crying for its receiver—was played on an Emulator keyboard, used to great effect on Freez's IOU and Martin Dupont's "Inside/Out"