If you use port 80, the default web hosting port, you don't need to include it in your URL, even for a media player...
Assuming you have a media server, and not just a web server, the media server would have to configured to stream the audio in random order. Else I should imagine you'd need to use something like Javascript to force it to play in random order.
Unfortunately I don't know how to do more than edit Javascript, so as for the code to do this, maybe someone else might be willing to write one up for you, or point out some resources which host some of these scripts.