Stepper Motor Choir consists of 12 stepper motors rotating on panes of glass. The vibrations of the motor resonate in the glass, which acts as a mechanical amplifier, producing a ringing tone. The pitch varies with motor speed and can be precisely controlled. Skylight-mounted solar panels feed power to the motors and an MMMSE. The motors sing according to available light. At rest, the silent motors eat light and store energy. Upon full charge, they commence singing. As the stored voltage dies, pitch and volume slowly drop. After several minutes they must stop and rest again.