The color organ uses both sides of the stereo output, mixes them together, and divides the music into four separate frequency ranges.  It includes microphone input.  Each channel has its own sensitivity control plus a master control.  Operates on 110v AC

Components:  20 resistors, 5 potentiometers, 9 capacitors, 4 diodes, 4 SCRs, IC, 2 transformers, slide switch, 4 outlets, line cord

Principles taught:  RC filers, SCRs, audio mixing