It’s not easy being young and beautiful and talented and in love. I conclude this not on the basis of personal experience, alas, but rather on the evidence of “Undiscovered,” a mawkish, self-loving bit of flimflam about artistic up-and-comers trying to make their way in the glittering jungles of Los Angeles.

The movie opens in New York, where smoldering balladeer Luke Falcon (Steven Strait) and his daffy brother Euan (Kip Pardue) fleetingly cross subway paths with the lovely Brier Tucket (Pell James). (Before you ask: Yes, all the characters and several of the actors in the film have names that appear to have been lifted from a 1940s comic book or assembled by means of some random word-association game.) Though they don’t have a chance to talk, Luke and Brier are mutually smitten. When she shouts, as the subway doors close between them, that he’s dropped a glove, he tosses her its mate as well. As her train departs, they trade interested grins.

But it’s not meant to be – not yet, anyway. Having evidently concluded that there’s no market for hunky singer piano players in the Big Apple, Luke is leaving for L.A. the next day. Cut to a musical montage (the first of several) that encapsulates the subsequent two years: Luke is making beautiful music in the City of Angels, but little in the way of cash. Brier is working as a model in New York and dating a British rock star named, of course, Mick. But modeling is so, you know, superficial, so she moves to L.A. to become an actress. There, she meets fellow actress wannabe Clea (Ashlee Simpson, playing a less-famous version of herself), who takes Brier out to a club to hear some music. Of all the gin joints in all the city, she walks into the one where Luke is unleashing his sensitive-guy-with-washboard-abs bebop.

Luke and Brier connect immediately but she refuses to date him, offering the mutually exclusive explanations that she is still dating Mick (at least theoretically) and that Mick’s constant infidelities have taught her to stay away from musicians altogether. The plot meanders along from there. Luke makes it big (with surreptitious help from Brier), fame goes to his head, and he falls back to earth like a meteor. Luke and Brier’s friendship slips into a single night of passion, after which she quickly retreats. Appearances are made by Carrie Fisher (as Brier’s agent and surrogate mother), Fisher Stevens (trying hard to rekindle his career with a Jeremy Piven-like turn as a sleazy record exec), and a bulldog that rides a skateboard. Lots of songs are sung.

It’s all watchable enough for a while. Ms. James and (especially) Mr. Strait have pleasant on-screen presences, and many of the early scenes have a light, genuine feel to them. But soon enough, the movie’s lack of narrative drive and breadth becomes a problem. The details of Luke’s singing career and Brier’s romantic indecisiveness play to diminishing effect, the former becoming melodramatic and the latter merely tired. Still, the focus never broadens: We don’t learn anything about the lives of Euan or Clea, or even about Brier’s own professional travails. (The message here seems to be that while boys have jobs, girls just have relationships.)

The movie’s lack of sustainable story line is perhaps unsurprising given that director Meiert Avis is best known for his music-video work. (His only previous feature film was released 16 years ago.) Mr. Avis’s training shows in almost every frame of “Undiscovered.” He is in love with the faux intimacy of the tight close-up, with beautiful people gazing soulfully into space while heart-tugging ballads play in the background. While his movie aspires to a kind of indie-film authenticity, it ultimately has the commercial soul of a music video. It’s always selling: its cast, its music, its moral. There’s much lecturing about the importance of artistic integrity and the evils of fame and careerism – an argument that is a tad rich coming from a film that stars Ashlee Simpson.

Toward the end, “Undiscovered” attempts to restore its flagging momentum by way of an escalating series of dubious coincidences and hackneyed plot twists – the appearance of a legendary, svengali-like record producer, a nick-of-time race to the airport, etc. These culminate in a hokey, unsatisfying solution to Brier’s I-can’t-date-musicians dilemma when, in the final minutes, Luke is offered the chance to embark on an alternative career. It’s just as well, though. His heartfelt crooning has by this point been pushed inexplicably offstage by Ms. Simpson, who usurps the spotlight for the movie’s final two songs. It’s a compelling reminder that some talents are better left undiscovered.