The new Home Sharing feature in iTunes 9 finally bridges the gap for homes, like mine, with multiple instance of iTunes, multiple iPods/iPhones and those of us who like to keep our libraries in sync as we purchase more and more content through iTunes.  So, what is the feature and how does it work?

Home Sharing works very similiar to the sharing features of earlier versions of iTunes, actually showing up in the same area of the iTunes interface.  Home Sharing, however, goes a step further.  By registering your iTunes with a specific iTunes Store account, other computers on your same network with the same account get access to pull music from each other – actually copying and keeping your libraries in sync.

Home Sharing also allows you to quickly and easily see what content in a shared library is missing from your library.  Once the home share is established and the list of content is populated, a drop down menu in the bottom of the app allows you to change the view to see only content missing from your library.  What’s futher, you can actually navigate the home share like your local library and limit the view to just music, movies, TV shows, etc. and then apply the ‘what’s missing’ view.

Taking it a step forward, you are also able to automatically sync music from other home shares to your library.  Some might ask why you’d want to do that…  Take this example.  At home, we have an iMac that serves as our master library.  We try to keep everything we buy there.  The iMac syncs to our Apple TV – so we want all our content there to be able to play it for parties or while we’re around the house.  We’ve enabled the automatic sync for music to pull all content from other home shares into this library.

I have privately hoped that Apple might enable this sort of functionality to turn the Apple TV into a digital hub and add the ability to make it a “master” library for iTunes, so the home sharing technology certainly gives me hope that this may come to pass.  I like the idea of having a smaller, headless device serve as my primary library.  But, until that time, we keep the iMac running 24×7 and so that works too.  Now, what about adding Back to My Mac functionality to iTunes so that we can get our home shares from anywhere on the Internet?  I like where this could go…