Enslaving third party players

Assuming playdar had a player api (stop start pause etc) it would need to delegate playback to certain third-party apps like rd.io or spotify.

Using the third-party player as an erlang port

One approach is to spawn the third-party app in headless mode:
./rdio.exe —headless
and send it commands on stdin, receive replies on stdout.
Commands might include:

• play
• togglepause
• stop
• setvolume <1-100>
• stat
  • which returns current NP data, position of playback (ie 120 of 300 secs) etc

stat could be emitted automatically on song change.

Using TCP/HTTP

The third-party app would open a TCP port on localhost, or run a small http server on localhost.
Send various commands over that port.

OS specific ways

Windows messages, or use a named pipe or something.