Well, I think you start with one of thesehttp://adafruit.com/products/322http://adafruit.com/products/306
and look at the tutorials/downloads that are available for each.
I don't follow how the lights are programmed to change with sound, not seeing the correlation there.
I do know folks here have done audio bar graph analyzers, focalist had one that showed quite a few bands on a TV, so the arduino can apparently do that well enough.
Here's another hardware optionhttp://www.roguerobotics.com/wikidocs/projects/rmp3/spectrum_analyzer_demonstration
From the page:
"Now for the weird and strange looking math. We need to translate a value into a vertical bar to be displayed on the LCD. It's a bit tricky, but not all that difficult.
The function below maps the value to match the number of bars (i.e. how tall? if you have a 2 line LCD, you can either use 1 or 2 bars). Then it draws the bar as tall as it needs based on the value. FYI: x refers to which column you are drawing."
I would hazard a guess that you change that part to instead send commands to the RGB LED strip.