With a few easy steps, you can transfer music saved on iTunes from your Mac or PC to your iPhone. You might need to do this to sync purchased music and ringtones to your phone (since Apple still won't ...

I just got my iPhone 5 and went to synch my music. I spend a lot of time on a plane and would like all 20GB of music on the device. I no longer have the option to sync my music from within iTunes.