After a bunch of troubleshooting with a friend who knew how to Arduino better than I did, we figured out how to actually get the lights to turn on (and blink!) when the switch was turned on. I didn’t want to ruin the wires or damage anything at all (or even risk it), so when I got home I ditched the “run the electricity through water” idea.
The code is the basic “blink” code included in Arduino, with the on and off commands set to 187.5 instead of the default – thanks to using a site to figure out the BPM of a song per millisecond, and then dividing that number by two.
I very much, from the start, wanted the lights to blink in beat to a song. While I had certainly edited the music in for better quality, I had actually planned on filming the whole song; but that would be too long for something that does not need to be long.