Prevent illegal Mp3 Download php

Hi there,

I am developing a application for a friend and they want to sell their own custom mp3’s instead of them being downloaded illegally is there anyway to do this to hide their location i found this very helpful but not sure how to go about it

Page 3 - Using PHP to Stream MP3 Files and Prevent Illegal Downloading

Can anyone help me here?

Store them outside the site root and serve them up via a PHP script that checks to make sure that the person requesting the download has purchased/permissions to upload the file.