This is probably not what you are looking for, but the first book that came to mind is Bel Canto by Ann Patchett. If you have not read this, it is a must. Great book!

The Ground Beneath Her Feet by Salman Rushdie might work.
Probably not the vein you are looking for, but High Fidelity was a great read.

If you like fantasy try The Lark and the Wren (Bardic Voices #1 or sometimes just called Bardic Voices) by Mercedes Lackey.

Music and Silence by Rose Tremain is really good. However, it is not about modern music -- it's set a few centuries ago.

I just finished reading Jennifer Egan's "A visit From The Goon Squad". I liked some aspects and not so much others, but it was about people in the music industry.

"The Song is You" by Arthur Phillips. Neurotic characters that you can't help being obsessed with whose whole relationship happens through music. Endless music refernces.

just remembered "Nick and Norah's Infinite Playlist"

Don't know why I didn't think of this earlier:

Love Is a Mix Tape: Life and Loss, One Song at a Time by Rob Sheffield. It's a very, very sad and touching memoir by a guy who ended up as a writer for Rolling Stone. Every chapter starts with a playlist. It's ALL about music and a REALLY good book.

Peter
(The guy who runs Flashlight Worthy)

Love is a Mix Tape is wonderful. One of my favorite reads in the past couple years. Sad but lovely. The author also has a new book out (ordered it but haven't read yet) called Talking to Girls About Duran Duran:

Technically YA, but eminently readable (and interesting for the London-in-the-1970s/80s settings), are K.M. Peyton's four novels of the rocky rise of her anti-hero, working-class classical pianist Patrick Pennington. In order, they are: Pennington's Last Term, The Beethoven Medal, Pennington's Heir, and Marion's Angels.

Maybe The Soloist by Steve Lopez.

a good companion to Bel Canto suggested earlier is As It Is in Heaven by Niall Williams -- music (including opera, a lot of classical) is interwoven into the character's lives.

also: Nick Hornby's High Fidelity could be considered a fictional version of the Rob Sheffield book (he relates all his relationships to mixtapes) and a good companion to that is Tom Perrotta's The Wishbones about a guy in a wedding band...

"King Dork" by Frank Portman is the ultimate Rock 'n Roll novel. It's Young Adult, but in the same way that Freaks and Geeks is a TV show about teenagers. Highly recommended.

Alesa - thank you so much for your recommendation! I loved that book. I'll be checking out more by Arthur Phillips!

Check out "The Glass Harmonica." I'm too lazy to look up the author, but it was quite lovely.

'The Speech of Angels' by Sharon Maas and 'The River Sutra' by Gita Mehta

War For The Oaks, by Emma Bull, in which a war between Faerie courts is fought with rock and roll.

bel canto its such a good book if i was to rate it of ten i would so say 10.