This wouldn't work for me because I don't listen to anything when I'm working. You're making the assumption that everyone is just constantly listening to music, but I focus best with silence and with my ears unencumbered. I suppose it would be doable with desktop speakers that would only play something when remotely triggered, but then there's the secondary issue that I'm not always at my desk, vs in the office people can obviously see who's there and who's listening in (and easily go grab someone else to join in as necessary). There's just way less friction to conversations when people are in the same room.