This script will attempt to get the CD Text information from the selected audio CD in iTunes and apply it to the CD's disc and track tags.
Some commercial CDs and commercial CD burning software (including iTunes as of v7.0) can use CD Text as a method of including text data on an audio CD. This data can include Artist (Performer), Album, Composer, Track Title, and Genre info. See the Read Me for more information.
Also see CD Text to Clipboard.
For OS X 10.7 and later.
In this example, all the tag data (except Year and Disc Number, which I supplied) are derived from the CD's CD Text.