Caillat's quick rise to fame shows on stage

Colbie Caillat performed all but one of the 12 tracks from her debut CD, "Coco," during her show Sunday at the Orpheum Theatre. (Justine Hunt/Globe Staff)

A gentle California breeze blew into Boston over the weekend in the form of a long-limbed, bronze-skinned beach babe named Colbie Caillat. She wore a sweet white dress and a flower in her hair and sang sunny pop tunes about magic and the little things and letting her feelings show. The girls in the audience at the Orpheum screamed "I love you," because that's what they do, but when Caillat's set was finished and the singer left the stage, nobody clamored for an encore.

It was a school night, after all. But the mass exodus was symptomatic of a darker weather system that lingers beneath the surface of Caillat's suddenly smashing career, and the 22-year-old singer-songwriter's first headlining tour is unfolding like a cautionary tale about the perils of a MySpace hit. Posting songs on social-networking sites provides extraordinary opportunities for aspiring artists to connect with music lovers, but it also turns novices into overnight sensations: Girls strumming guitars in their bedrooms are scooped up by major labels eager to cash in on the built-in customer base and foisted onto theater stages long before they're ready to be there.

Caillat's concert was nearly surreal. She has the big single ("Bubbly"), the devoted fans, the polished five-piece band - all the trappings of pop stardom, but none of the expertise. That's not to say Caillat is without charms. She's armed with a lovely singing voice and a pocketful of slight, well-crafted songs, from 2007's "Coco," that play like the soundtrack to a prime-time teen drama. But Caillat was like a lost lamb onstage, pacing tentatively or positively inert. The music and the mood followed suit.

Caillat performed all but one of the 12 tracks from her debut, one new song and an older one, and a cover of Bob Marley's "Turn Your Lights Down Low." Opener Jason Reeves, Caillat's co-writer and musical doppelganger, joined her for a bouncy duet on "Realize," the follow-up to her catchy calling card, "Bubbly," and the comfort of a friend freed the singer to briefly kick off her heels, literally. But otherwise none of the songs seemed to engage Caillat much. Tapping her hand on her hip, or gazing into the distance, Caillat gave a performance that toggled between pleasantly meek and dreadfully temperate.

To its credit, the band pulled back as best and often as it could, giving the frontwoman every opportunity to shine. But the light wasn't on. The question is whether or not Caillat will find the switch before the short, brilliant shelf life of an Internet phenomenon expires.

Joan Anderman can be reached at anderman@globe.com. For more on music, go to boston.com/ae/music/blog.