She’s got a voice (and a heart) full of spirit

MIDWAY through Brandi Carlile’s 19-song set Tuesday at the Troubadour, her tight-fitting suit jacket began to creep open at the neck -- which was bad, Carlile explained, because she wasn’t wearing anything underneath it. Per rock-show protocol, this elicited enthusiastic cheers from the capacity crowd. “Hey, I’m not that kind of girl,” the 24-year-old Seattle native said with a laugh.

A fresh-faced beauty with the kind of tumbling tresses seen in shampoo ads, Carlile seems uninterested in exploiting her looks; she subscribes to the school of the singer-songwriter, where all that matters are songs and a voice.

On record, that puritanical sensibility yields results that can bland out into coffee-shop background noise. Like her 2005 debut, Carlile’s new sophomore disc, “The Story,” features some strong folk-rock writing but never really distinguishes itself from millions of CDs by similar artists working in a post-Norah Jones mode.

In person, though, Carlile’s uniqueness is apparent from the outset. As one fan put it on Tuesday, “God, you’ve got a voice!” An old-school country fan young enough to have been moved by Nirvana, Carlile sings sweetly, but pushes her voice to teen-spirit extremes, packing entire albums’ worth of emotion into a line or two.

At the Troubadour, she was backed by a band that included her two principal collaborators, Phil and Tim Hanseroth; they lent muscle and texture to Carlile’s material, as well as spirited Beatles and Johnny Cash covers.

Yet the show’s best moments occurred when Carlile’s sidemen made way for her amazing instrument, as in a heart-stopping rendition of “Hallelujah,” the Leonard Cohen gem Carlile called her “favorite song in life.” Joined onstage only by her friend Arnold McCuller, she made the long journey from whisper to scream, then came back again.

No one said a thing about her jacket.