See http://www.rdio.com/developers/docs/web-playback/index/ for API documentation.

Methods include: rdio_play([key, [options]), rdio_pause(), rdio_stop(), rdio_next([superSkip]), rdio_previous(), rdio_seek(position), rdio_setShuffle(shuffle), rdio_setRepeat(mode), rdio_queue(key, [options]), rdio_setVolume(volume), rdio_setMute(mute), rdio_playQueuedTrack(position, offset), rdio_moveQueuedSource(from, to), rdio_clearQueue(), rdio_setCurrentPosition(sourceIndex), rdio_removeFromQueue(sourceIndex), rdio_sendState(), rdio_startFrequencyAnalyzer(options), rdio_stopFrequencyAnalyzer()