Looks pretty neat, reminds me of a private Turntable.fm, Plug.dj, or Soundtrack.io.<p>FYI: I managed to break the flow on my first try. I clicked on the number discs, thinking they were some kind of step indicator, and I ended up selecting the 3rd one. When I was prompted to pick tracks, I ended up stuck in a loop as I had not set track 1 or 2 and thus could not continue.
Nice! I've got a similar project currently in the pipes.
I've noticed that the playlist can get pretty out of sync when one of the clients disconnects and reconnects, sometimes by a few minutes. But otherwise really well done.