What if a Lethem novel were to do for L.A. what Motherless Brooklyn did for Brooklyn—make it more real, more variegated, more autobiographical than the place itself? Since he’s reworked his life growing up in the not-Manhattan again and again—with diminishing freshness—it was definitely time for a change. You Don’t Love Me Yet takes a flyover to the coast sinister in the 80’s, when Mr. Lethem was living there and playing in a rock band. On the cover of the novel is a photo of an anorexic young Johnny with earring and guitar; inside is his portrait of the faltering and the fameless.

They’re an insouciant bunch, trailing names in the Henry James vein (Lucinda Hoekke, Matthew Plangent, Rhodes Bramlett, Fancher Autumnbreast), and I’d swear that the opening scene, in which Lucinda and Matthew meet in the neutral space of a museum lobby to break up for the umpteenth time, cribs from James’s story “Julia Bride.” (They end up having sex inside a Conceptual artwork—so not The Master.)

That impromptu love shack is an early piece by Lucinda’s friend and employer Falmouth Strand, who has now moved on to more interactive art installations. Lucinda’s job, along with the other assistants in his gallery space, is to take notes from her conversations with callers phoning in over a “complaint line.” (The telephone number is helpfully included.)

Where You Don’t Love Me Yet pretty successfully gets the reader is inside the group life of an aspiring alt-rock band, its rehearsals and its gigs, its ambitions and uneven talents, its flash-in-the-pan hits and sexual crushes of only slightly longer duration—at one point, Matthew, a part-time zookeeper, romantically kidnaps a depressed kangaroo. There are other kooky and well-aimed moments of comic relief, which help make up for the occasional character selections from central casting.

Where it gets Lucinda is into an intense new affair with her favorite “complainer,” an older man of substantial means and the requisite Hollywood sleaze quotient. Matthew’s obvious opposite, he’s made a fortune writing slogans, most likely among them the freeway rallying cry “You can’t be deep without a surface,” the perfect war whoop for the self-serious. But Mr. Lethem doesn’t belabor the old saw of a superficial Hollywood Babylon (though he also knows his Nathanael West—Lucinda as Miss Lonelyhearts, anyone?), lighting instead on the slippery meeting points of the make-believe, the actual and their strenuously jaded go-betweens.

Maybe it’s a 21st-century thing, but you can’t always count on Mephistopheles to keep his end of the bargain. Is that such a bad thing? The band will find out. Sometimes, passable lyrics come out of it—and, in this case, an entertaining novel.

Celia McGee is a book critic and arts writer who lives in New York.