When you initally posted this problem, although you had included the mp3s in the project, seemed to me you wanted to dynamically load those mp3s and stream them, which to me was a better solution, since your .swf is now over 1MB, and for slow connected users, this is going to take quite some time to download.
As for your preloader, the way it's coded, it won't ever work. A preloader is basically a loop that checks to see if some condition is met. In your preloader there's no loop. So minimally you would at least have to add a second frame to your preloader, so that it loops until the condition is met...
gotoAndPlay(1);
But since Bill used the attachSound action, rather than the loadSound one, and although the preloader might still be working, it will not display properly until all mp3s have downloaded on the first frame. One workaround is to create a new preloader only movie, which only prupose in life, is to preload your present file, without it's own preloader.
Furthermore, if you ever load this player, in another main movie, my guess is that the sounds wouldn't play anyways, because the sound objects' definitions are not properly coded and set.
Regards,