how to sync music in itunes to iphone
1 If you want to manually add music to your iPhone, you can drag songs from your iTunes library onto your iPhoneâs icon in the iTunes side bar. 2  If you want to use up all the space on your iPhone and fill it with music, check the box next to Automatically fill free space with songs on the Music screen in iTunes.e sure you are using the Apple Dock Connector to USB port cable that came with your iPhone. 1  If your computer has USB ports on the front and back, connect to a port on the back of the computer. 2  If iTunes does not recognize your iPhone when you connect it, try closing and re-opening iTunes.