This plugin will let you have a Blofeld server as a source in Rhythmbox. Unless
you have a Blofeld server, or know someone who does and has given you access,
then this won't do anything for you. You can find out about Blofeld by visiting
http://github.com/daveisadork/Blofeld 

To use this plugin, you need to stick these files in a folder inside of the
Rhythmbox plugins folder. You might accomplish such a thing like this:

  cd ~/.local/share/rhythmbox/plugins/
  git clone git://github.com/daveisadork/blofeld-rhythmbox.git blofeld

Then you should have a directory at ~/.local/share/rhythmbox/plugins/blofeld
which has a few files in it. 

Now you can launch Rhythmbox and enable the plugin (hopefully). Then, hit the
configure button and adjust the address, username and password to values that
make sense. You should have Blofeld listed as a source. Now you can listen to
music, yay!