Hello blh64 !
Thank you for taking the time to reply.
I know that the wave shield is not meant for the mega but I followed some tutorials to hack it and it works just fine for me. I relay needed the mega because I'm controlling a servo, a PIR motion sensor, buttons (4 Channels RF Remote Module) and the wave shield.
For the moment I can control input/output af all the different components.
The tricky part where I realy need some help is to do just as you said : "read in the song list and store it in an array rather than print it out".
How do you do this ? This seems complicated for me because I specialise in Java and not C language.