I have finally found some time to get the spectrum analysis working on the LED matrix. As you can see in the picture I am using the breadboard which I have my playback control circuit on to provide the audio signal to the arduino. This is then processed using the FFT Library and finally displayed on the matrix. At the minute I can only use one color and I am not happy with the refresh rate so there is still some work to be done. Eventually I hope to have a red dot for the top of each column which will detach itself if the column drops suddenly and fall at a steady rate.