Apple keeps the music files on your iPod hidden, but with a little hackery, all your music will be revealed, allowing you to copy the files (legally, of course) from one machine to another.
If you have ever activated your iPod's Disk mode [Hack #32] and taken a peek at the disk in either the Macintosh Finder or the Windows File Manager, you might have found something missing—your music, that is. Sure, it shows up in iTunes, but where is it on your iPod? Hidden, that's where. In order to put some muscle behind the label that is slapped on every iPod (in multiple languages)—"don't steal music"—Apple hides the iPod's tracks in disk view.
Sneaky. But not quite as sneaky as us iPod/iTunes hackers. Of course, we are not doing this to steal music! We are doing this because we want to be able to copy our music from our iPods to our other machines, so we can listen to it in iTunes on those days when we accidentally leave our iPods at home, at the office, or at a friend's.
Since the music files are invisible, all we need to do is make them visible. Computers actually use invisible files quite a bit to store, for example, system-related information that you should never see or open. However, both Mac OS and Windows make it easy to view and search invisible items.
Launch the Terminal.application and type: