mauirixxx

as far as I know the only official way to get music played natively on the iPhone is to transfer them via iTunes via your computer, or via the iTunes store on the phone. There are apps that support playing music uploaded directly via the app itself, but the default music player can't see those (and that is by design). So unless btsync bakes their own music player, having your mp3's backed up to your phone won't do any good unless it supports sending the mp3 to another app that CAN play them.