February 17, 2010
One of the great things about iTunes is having your whole library in one place, every track available for any playlist and whim. But it's only great because that place in turn lets you enjoy your library everywhere, and not only because it handles syncing with your iPhones and iPods. iTunes is local network smart, which makes possible Home Sharing, for instance, plus participating in sharing over your local network (work, dorm, etc.) via the Sharing tab in the Preferences panel. And in the Devices tab the "Look for remote speakers connected with AirTunes" checkbox enables still another kind of local network capability.
Apple's Airport Express Wi-Fi base stations come with a technology called AirTunes and include an audio minijack for speaker systems. Plug the Airport Express into the wall near your speakers and add it to your network (or use it to create a network), then plug the speakers into that minijack. Your AirPort Express will now show up in a pop-up menu in the lower righthand corner of the iTunes window as one of the places you can pick for the music to come out. Checking "Look for iPhone and iPod touch Remotes" will also make it show up as a Speakers choice in the free Remote app available from the iTunes App store. All the shared libraries are available via the Remote as well.