Welcome to the forum, Sunapee!

The EX's Music Box is pre-loaded with a version of the Gracenote CD database (formerly known as CDDB). When you insert a commercial CD, this database is used to obtain the matching information based on a signature.

To account for commercial CDs that become available after the database snapshot was done, Infiniti provides a downloadable program:
Infiniti Music Box Updates by Gracenote - Infiniti USA

The above link simply allows you to obtain album/track information for CDs not covered by the data pre-loaded in the Music Box, by giving you a program to connect to the current (presumably updated), Gracenote DB over the Internet using a computer. The full illustrated instructions are provided, but be warned you'll need a CF card.

That said, some EX users have complained that it doesn't work for them. Now, whether Gracenote hadn't updated their online database or there's some fault in the supplied program, I can't say. The phrase "your mileage may vary" seems apt here.

Hope that answers your question. Good luck!

David