Using a 4017 CMOS circuit and some passive electronic components, can be build an color lights organ with LEDs. This lights organ LED is controlled by a signal that is picked up by a microphone.
Speed of light depends on the frequency and intensity of sound.
Signal applied is to the clock input of counter IC1 through an amplifier with one transistor T1.
After amplification, the signal is applied to IC1 by P1, which controls the sensitivity of the circuit. Because audio frequencies are too high to produce a quality visual effect , frequency signal is divided with IC1 when S1 connects pin 11 with pin 15.
Of the ten outputs of IC2 of each coupled to each LED, there is always one in state 1.
The power supply must be able to provide a current up to 100 mA.