Hi, My iPhone 4S operating on iOS 6 won't sync any of my music on iTunes. I've tried everything, but every time I sync some music to my phone, it doesn't add it. Instead, the music from my last working sync stays visible on my phone, but when I go to play it, it just skips quickly through the entire album/playlist but doesn't play anything. It's as if it has deleted all the unsynced music but not the image of the file on my phone. Also again, my iTunes won't add any new music at all. Whenever I add new music, it acts like it's going to sync, and the memory bar on the bottom of iTunes even adjusts, but after the sync process the bar resets, showing my iPhone's memory without any music whatsoever. I've had my phone for almost half a year and this has never been a problem until last night. I would appreciate any help, thanks!