Doubles is an electronic music instrument with a tangible user interface. Using two physical objects on a table, several simultaneous performers can interact with the instrument which registers the speed, distance, and motion of the objects. The surface of the table is paved with beads that roll when the physical objects are moved. This creates a sliding effect of acceleration and a centrifugal force is created to compute the audio and visuals in the installation. Check out the video below to see the visuals and hear the strange sounds produced by the instrument.