Is there any way to play more than one song in the BG, but one at a time?

Say I have two files, intro.mp3 and loop.mp3.

What I want is to play intro.mp3, and when its done playing, to play loop.mp3 and loop it 3 times.

Is there any way to preload the songs before they play so that there isn't a gap between when intro ends and loop begins?

I also made copies of the files with whitespace inserted so that if I had to have them both play at the same time, loop wouldn't have any music until its supposed to, but again, I need to preload the songs before playing them.

I have no problem having the music not play by itself, but rather have the user click a button first after the songs have been loaded, but I don't know how to do this at all. I've tried several things but ntohing seems to work.