It looks like
Originally Posted by bobsilver
This is an iTunes compatible server that will work with IOS devices. When I met with the product manager I was clear on this point as this is something I want. I currently run a copy of iTunes on a server which is a pain. If you look at the R7000 marketing material you will see it refers to iTunes server and Airplay support. But I will use it first and then confirm it for you all.
they are using forked-daapd or their own in house variant to connect the stored music library to the Apple iOS remote app, but the OP is looking for something which automatically stores and streams their iTunes purchases something the iTunes server on the R7000 cannot do. In your case you will still have to turn on iTunes to have it auto download the tracks to the USB drive attached to the R7000.
As DoctorVideo says iTunes match is another approach if your okay with all your content in the cloud.