Go2Linux posted a tutorial about streaming music with gnump3p and Linux

If you have a big collection of music, you can’t have in all your computers, so you'd better have it only in one of them and share it with the others.
There are a lot of ways to do that, you can use Samba, NFS, or other means to share you drive with others, and thus your music collection, but a better way IMHO, is to share it using a streaming server.

  Streaming music with gnump3p and Linux - mp3, ogg, movies | How to