been trying to balance etiquette vs functionality for working with multi-zone audio. this is Eva's current setup.
1) starting music
you can only start music for the zone you are speaking from.
2) transferring / sharing zones
you can only transfer music or turn music zone on or off for your current zone. these rules avoid somebody turning on music and then transferring it to a zone where somebody is sleeping. but a friend pointed out a problem ... this also keeps you from saying 'play artist marvin gaye' and then 'transfer music to bedroom'. wink wink. there is still the issue of zone 'tug of war'. so somebody else could start music in their zone. then you could transfer it to your zone. then they could transfer it back, etc... but i like being able to tranfer music from anywhere, because that favors the lazy user. e.g. if i left music playing in my upstairs bed room, then i dont have to go back upstairs to turn it off, i can just transfer it to where i am, and then stop it.
3) music control
you can only control music for the zone you are in, or for shared zones as long as you are in one of those zones that is shared. this avoids somebody in a different zone changing your music.