This digital color organ tracks both the amplitude and frequency of the sound input. In operation the phone output of a transistor radio can be connected directly to the input of the LM3915. Sensitivity is adjusted through R2 and may need to adjusted if the volume is changed. The display unit consists of 10 tricolor clusters of LEDs with red representing low, yellow midrange, and green high ranges. 2 gates of a 4011 are used to make a clock, which can adjusted through R6, and fed into the clock input on IC2 (4017). When there is no sound the display will be blank. Once a signal is present the display will come to life with bursts of light and bars as the signal is tracked. Resistors R4 and R5 can initially start with a 1Kohm pot to achieve the best balance and replaced with fixed resistors once this is determined. The display can be expanded by cascading additional 4017's and LED clusters.