Having a backup of your music files is excellent insurance against all sorts of music-library corruption. It’s also a safety net for all the music you’ve bought from the iTunes Music Store; if something goes wrong with your hard drive, and you don’t have a backup, you have to buy all of it again.
If you’ve got an external hard drive (the hard drive in another Mac on the network counts), backing up your music collection is extremely easy. Open your Home → Music folder, and copy the iTunes folder inside it. That’s it—you’re backed up. (In the event of catastrophe, simply restore this backup copy to its original location.)
You can copy about 650 megabytes of music files to a recordable CD, or (if your Mac has a DVD burner) about 4.7 gigabytes to a blank DVD.
Start by creating a playlist of your entire music library, like this:
In iTunes, click Library in the Source list.
Make sure that the Search box is empty—that you’re viewing your entire list of songs.
Click a song, and then choose Edit → Select All.
iTunes highlights all of your songs.
Choose File → New Playlist From Selection.
iTunes asks you to name the new playlist.
Type Full Backup (or whatever name you like).
Now you’re ready to create the backup disc.
Choose iTunes → Preferences; in the Preferences dialog box, click Burning. Click “Data CD or DVD,” and click OK.
You’re going to burn a computer disc, that is, not one intended for playing ...