You are completely correct

I never thought about pulsing LEDs in time to the music! (well, I did as an independant idea, and not relating to the empeg :P )

Can someone please re-post where we can get spare buttons from? I would like to cast my own, make an amateur mold, etc. but do not want to wreck or remove my current buttons. I have not been able to find the part number & supplier from searching the forum archives :|