Alvin Lucier’s Bird and Person Dyning (1975) is a composition for a set of binaural microphones, a pair of loudspeakers and artificially generated birdcall. The only visible feature of the composition is the performer’s slight movement in the space. This creates feedback between the microphones inserted in the performer’s ears, the birdcall and the stereo system. The listener listens to the composer listening whilst the simplest playback devices and the acoustics of the space create a variable sound image.