Hello 
. I have setup my Arduino with a relay board to control my Christmas lights through vixen. The problem i have is songs take forever to program so i want a Vu meter that uses the serial port for random songs. what would i need to do to make my computer send the sound through the com port & what would i need to do to make my Arduino take the data and convert it into lights?
It would take a miracle of biblical proportions.
what you need is a color organ, it will allow you to use an MP# player and a Y splitter to plug your arduino into it and get the notes as well as an amp to play the music itself...
another solution would be :
i have attached my RTTL ino it has almost 30 christmas songs in the included library
stuff1.zip (499 KB)
also see FFT Library - Audio - Arduino Forum