You could email the site author for either:
- a download of the original music
- the authorization to record it off the stream.
It's trivial to record music off a stream, just get the free Audacity program and record the wave output of your sound card (for most sound cards you don't need a cable or anything), then you can encode it to whatever format you want (I do MP3 using the Lame pluggin for audacity). Just make sure that no other program on the computer is going to make a sound while you record (like incoming email notification) or that would get recorded too.