Apple iTunes Home Sharing, can it be setup, storing the iTunes media library on an external drive, attached to an Airport Extreme

I have a 27" iMac, as my main computer @ home in the "ManCave". I also use an AppleTV, MacBook Pro, & iPad 2, @ home in the bedroom. I have an Airport Express to extend the Comcast Xfinity home network on the second floor in my bedroom. I plan on adding or subbing in an Airport Extreme. Currently, I store all iTunes files on a 4TB External USB3 drive. I want the ability to share with all my Mac Hardware @ Home over the internal home network, can it be accomplished through the Airport Extreme? Thanks for any assistance you may render.

Mark Metzler