Microphone light effects synchronization
Michophone syncing improves light shows greatly. Most simple synchronizer is audio pressure sensor (microphone with comparator).
Advanced variant will create some sort of buffer to keep BPM rate, result in slow rate change. This enables curious effect: in
case of unexpected beat stop, output BPM rate won't rapidly falling to zero, still triggering lights to change, but slowing.
Once beat is returned, output rate increases if it is lower than input rate.
Also, FFT can be used instead of microphone filter. This will increase beat detector precision.