I've made a couple of simple kits: look for "light organ", or color organ" these were activated by either a line-in input from a sound source, or some smaller versions use a microphone. I'm not sure what your power supply will be. I made one that uses 110AC and then I wired 3 regular outlets to plug strings of light into for low, mid, and high tone ranges. Basically they dim or brighten, and flash as a whole string as volume goes up and down. http://www.canakit.com/3-channel-ac-col ... uk185.html
For sequencing lights to music, you'll enter territory I haven't travelled in.
Jungle smacks has a thread as well for light controller work he is doing.
then if you are really computer savvy.. as in programming... you can look into arduino boards. I know nothing here, just repeating something I've heard of.