I've re-read this slim volume a number of times because it's a quick, effortless and enjoyable enough read; I just re-read it again after getting it back from a friend to whom I'd loaned it, and i thought i'd comment.
I should say that this is the only novel of Kennedy's that I've cared for. The structure with the four chapters, each dedicated to a single band member, is a clever device and gives the reader a chance to get into the mind of each character separately.
The character that i felt was most interesting was Shaz, the bass player; she and her section were the most developed back-story-wise, since most of her part is a flashback, but we also get more information and description regarding her family, peeks into her unusual job and her apartment than with any of the other characters. The story of her ex, Walt the drummer, is also enlightening because throughout the rest of the book he comes of as an awkward enigma, so to get into his head at last is fulfilling. Walt's story also gets a different tone from the rest as it's told all in present tense.
I was less inspired by the other characters; Hank, the guitarist, gets fairly typecast as the wannabe rocker whose personality takes a downturn once the band gets going in earnest. His chapter is somewhat skimpy regarding himself since half of it is taken up by information about Lilly, his former girlfriend who comes up with the Exes concept. Given Lilly's personality (a hyperactive, self-centered and somewhat bratty attention hog) it's fairly appropriate that Lilly takes over some of Hank's space, though her section would have been more than enough for the reader regarding her character. Lilly does evolve somewhat as the story progresses, though her whininess remains intact throughout and does get old. The book could have suffered from having these two characters composing the first half of the book (though plot-development-wise it couldn't be any other way, really), but they're not annoying enough to make you put the book away because of them.
A big theme in the book of course is that of relationships, but some aspects of this get strained; one example of this is the appearance of Lilly's new boyfriend Dieter, a cheezy stock intellectual character whose personality completely changes once Hank befriends him. I have a hard time believing that someone of that temperment would even be able to stand Lilly, much less date her, or that his personality would make the complete 180 that it does, even with Hank's trying to shape him. Also, it's hard to imagine Shaz and Walt ever dating (Walt's section delves into this somewhat), though for the purpose of the story it's a necessary device.
This book is more about the characters than the actual music, which is fine since it's hard to get a sense of their music without actually being able to hear it, though there are some lyrics sprinkled throughout. I wasn't bothered by the lack of the techincal aspect, though perhaps this would frustrate a more musically-inclined reader.
This book comes across as slightly dated now as it's set in the mid-late 90s alternative rock scene, so references like miniskirts with combat boots and the like seem a little stale, but overall that doesn't detract from the whole.
This book is decent as a quick read; if you try to take it too seriously and are hoping for a "High Fidelity" or such you'll probably be disappointed. Still, it's worthwhile.