The movement of a pendulum is tracked by a spiral of sixty-four sensors. As the pendulum passes over a sensor a sound event is triggered. As the pendulum traces its trajectory, we experience repeating patterns of sounds. In reality, however, these patterns are constantly changing as the effects of gravity, air resistance and friction dampen the movement of the pendulum. Sounds are lost from the pattern as the pendulum’s trajectory decays but sounds can also be added to a pattern if circular or elliptical movement contracts to include sensors closer to the centre of the spiral. This installation alternatively utilises sounds derived from recordings of a classical guitar or of a prepared piano. My thanks to Greg Caffrey and Simon Mawhinney respectively for assistance with these recordings.