Q: I have just updated my iPod, and iTunes displayed a message saying that some songs in my iTunes music library were not copied to the iPod because they could not be found. Those not transferred have a ! icon next to them. How can I get these songs back into my iPod?
A: When iTunes cannot find songs, it does what you describe: the ! icon shows which tracks it could not find.
This generally happens when you delete song files from your computer (but not from iTunes), when you move song files to another location, or when the original location (such as an external hard disk) is not available. If you want to transfer them, you’ll need to find them.
If you’re sure that these songs are still available, search for some of them on your computer.
If you find them, you can double-click on the individual songs to have iTunes ask you to locate them; it will then update its database with the correct location.