I would like to use a sound track to dim a string of Christmas lights (ie: the volume is inversely proportional to the light intensity, though I can deal with the reverse). I have a scary-terry set up and a dimmer, but the servo is too fast, so it is all or nothing. I want a slow pulse with some erratic stuff thrown in the mix. Any ideas? I would like to do this on the cheap and this is my first venture into the whole animatronics thing (scary-terry is as complex as I get right now).