How to Sync Music From an iPhone to the Computer on iTunesby Shawn Farner
If you purchase music on the go using your iPhone and its built-in iTunes Music Store, it's a good idea to save your newly purchased tracks to your computer. You can do this using the same process you use to transfer music from your computer to your iPhone -- syncing. An iPhone's sync works two ways, so music is transferred to the device as well as from it if purchased on the iPhone first. You can learn how to sync music from your iPhone to your computer by following a few steps.
Open the iTunes application.
Connect your iPhone to your PC using its included USB cable. Allow between five and 10 seconds for the iPhone to be recognized by iTunes.
Click the 'iPhone" link under the "Devices" section on the left side of the iTunes application.
Sync your iPhone with iTunes by clicking the "Sync" button at the bottom right-hand corner of the iTunes screen. Not only does this action sync your iTunes music to your iPhone, it also syncs music purchased using your iPhone back to your computer.