I am curious to hear the answer in regards to this question; how will the expansion music be handled when the expansion is toggled off (when released)?
If the user has an expansion key but has it toggled off, will they still have client-side access to this music, or will it be turned off? I can assume the trouble here is perhaps ensuring the user has the full version of the expansion; else regardless have the music turned off if the expansion is off. This is not to say that people who don't own it should be able to listen to expansion music.
All my best regards to Pablo!