There was a guide a year or so ago on this forum about making LED-lit buttons, I'll try and dig it up. I know kitsch has been working on silicone-like buttons with LED holes for at least a year (it's somewhere in his shop thread), but you can drill your own holes and put the LEDs in yourself on clear buttons (you may want to sand the outside to change the light diffraction, as well as cut notches for the LED legs to escape through for wiring in series).
Hard to execute, almost ALWAYS stunning when done looks great!
Yeah, I imagine this is the easy bit though. Getting the LEDs to be sound reactive with the DMG's audio?