Shema.org is great for rich serps. But I have seen this before even for my own site without using shema.org.
I guess its relevance and how your site is built. For instanse if your site (lets say yoursite.com/music) is a feed witch displays new elements all the time its not unusual to se results with some text and then +15 elements showing titles and ratings if that is a part of your content. Remember shema.org is pretty fresh and we have seen rish serps before that
Itunes is a BIG brand so for google to manually build this is a great reward for googlers.
So basicly my answear is build your site so that its easy for google to crawl AND include shema.org to be on the safe side and get it as you want it.