Of course Apple could use narrowly focused data like your iTunes example, but that's a far cry from collecting anything and everything. There's also nothing stopping them from having that data collected and processed locally so it never leaves the device. There's no reason it needs to be uploaded off your phone, other than to combine it with other devices like an iPod, Mac etc. which would be of limited utility unless you listened rarely on your phone compared to other devices.
Please spare me "just because Apple says they aren't doing it doesn't mean they aren't doing it". Just because Google's stated policies don't allow them to make every scrap of info they collect on you available to all governments of the world, as well as selling it on eBay for your neighbors to buy doesn't mean they aren't doing it, right?