This code generates random sequence, plays music, and displays button lights.
Simon tones from Wikipedia:
G (yellow, lower right, a perfect fourth higher than the lower left) - 784Hz - 1.276ms - 0.638ms pulse
Simon Says game originally written in C for the PIC16F88.
Ported for the ATmega168, then ATmega328, then Arduino 1.0.
Fixes and cleanup by Joshua Neal