With Raveberry 0.5, you can not only remotely vote for the music you want to listen to, this music can also be streamed over the internet so you can enjoy it together.
It works by configuring Mopidy to stream its output to Icecast, which is then exposed at http://raveberry/stream. This stream can simply be opened in your browser and a variety of media players and clients. More information about how to set up streaming can be found here.
In order to make your Raveberry instance reachable from outside your network, you have multiple options:
If you have access to a public server like a small VPS, you can set up redirection from there. An example nginx configuration can be found here. If specified during installation, Raveberry can now automatically connect to this server and open a reverse ssh bridge.
If you don't have a public server at hand, you can set up port-forwarding on your router. For example, map port 7247 of your router to port 80 of Raveberry. It is then reachable from the outside via http://\<external-router-ip>:7247. You can also set up Dynamic DNS so you don't have to deal with your router's ip changing all the time.
You can create virtual local networks over the internet, allowing everyone in the VPN to access Raveberry. However, I did not test this yet.
If everything is up and working, you can listen to the music from anywhere at http://\<Raveberry>/stream. Voting and requesting of music works like before. Let me know what you think!