Comment 3 for bug 943607

It only happens with Spotify, yes. No, there is no dialogue except for the normal 'are you sure you want to shut down'. Clicking 'shut down' in that dialogue simply closes the open Spotify window, it does not quit Spotify itself (Spotify still plays music and the indicator is still there). It does not seem to affect any other part of the OS or any other applications.

If there is no open Spotify window Ubuntu shuts down normally.