Gameboy + Casio SK-1 with Birdfeeder Control Panel
Here we have a modified gameboy, whose controls are mounted on an attached case (made from some other toy, gutted). The pitch and speed of the gameboy can be controlled by knob or by light sensor. The SK-1 is attached to the gameboy via 1/8" cable so that both instruments are running off of the same LTC1799 clock and can be affected by the light sensor simultaneously.