I collaborated with Jonah Elgart in 2013 on a prototype for a musical gears construction kit that lets you create complex rhythmic patterns. A large gear in the center turns smaller gears that you place around it, which go around 2, 3 or 4 times for each turn of the larger one. They have holes for pins around the edges. As an outer gear turns, its pin pushes back a Lego lever arm tensioned with a rubber band, and the arm snaps back and smacks a percussion instrument (or any other object). The combination of the different sizes of the gears and the placement of the pins on each gear lets you create a variety of different rhythmic patterns.