You need a magic box, yes, unless you have a 2011 Denon, Pioneer, or (I think?) Marantz with Airplay. The magic box is either an Airport Express or an Apple TV.
An airport express is also a wireless extender, so if you go that rute, your wireless internet signal will be stronger in the house. I have 2 of them, and they integrate well with i-tunes. You name them, and then in itunes you can choose "which room" you want to send the signal to.
I think you have to use itunes for this to work though.. I don't know if that is a big deal for you or not. If you do use itunes though, itunes control is integrated into pretty much all of apples products now.
