Natalia Lafourcade at the Conga Room

With early-bloomer musicians such as Natalia Lafourcade, there’s sometimes a thin but crucial line between precociousness and preciousness.

When this gifted Mexican pop-rocker released her self-titled solo debut in 2003, she was not yet 20 summers old. But Lafourcade -- a daughter of musicians who grew up singing mariachi and who plays guitar, piano and several other instruments ably and writes or co-writes most of her material -- already had attained a mature songwriting style that wrapped delicate emotional introspection in sly wordplay while seldom stooping to mere whimsy.

Her primary subjects were pretty standard late-teen fare, gently exasperated expressions of romantic uncertainty. Her lyrics could mix playfulness with passion, longing for Ricky Martin and lusting after Gael García Bernal. Yet these effusions mostly came across not as fangirl gushing but rather as a sophisticated young woman keeping her humor intact while striving for self-knowledge. Like one of those preternaturally flexible but muscly Olympic gymnasts, she was a petite dynamo, effortlessly appealing and wise enough to keep the cuteness meter dialed down to around 6.

On Thursday night, Lafourcade’s nearly two-hour set at the Conga Room testified to her growing maturity as a songwriter and, even more, a mastery of her shape-shifting, dynamically intrepid voice. Technically a solo artist again, after releasing her second album, “Casa” (2005), with the band La Forquetina, Lafourcade was accompanied only by a bass player and a kinetic percussionist. Playing virtually her entire latest record, “Hu Hu Hu,” released last spring, mixed in with a few “oldies,” she echoed and amplified her bright harmonies with reverb, sampling and looping techniques that at times recalled the piercing minimalism of early Laurie Anderson.

Leading off with “Amarte Duele” (Loving You Hurts), from her first album, Lafourcade, now almost 26, remains a polite, shy, occasionally distracted stage presence. She wore an oversized blue pullover, gray miniskirt and ankle-high boots, her hair pulled back in a ponytail, and punctuated her show with giggles and apologetic murmurs when she paused to tune her guitar or fetch another instrument. Once she forgot a song’s lyrics and had to start over.

Resilient vulnerability is her narrative forte. In “Cursis Melodias” (Tacky Melodies), “No Viniste” (You Didn’t Come) and many others, her voice hovers between a plea and a reproach toward an erratic paramour. “I was very frustrated when I wrote this song,” she said in Spanish, introducing “Running Too Fast.” “I hope you like it. It’s a little sad.”

Lafourcade’s momentary glumness, however, rarely overstays its welcome; eventually, her buoyant humor and fierce intelligence reassert themselves.

“Ella Es Bonita” (She Is Beautiful) she sings sweetly in poisonous praise of a rival. “Azul” means “blue” in Spanish, but Lafourcade’s song of that title is less a soulful Delta lamentation than a cri de coeur that swells and rises into a womanly war whoop. Her scale-sliding voice has no trouble handling such abrupt dynamic shifts.

“Un Pato,” from the movie “Temporada de Patos” (Duck Season), could be a Rafi nursery tune, with its onomatopoeic animal sounds and accelerating tempo, like a duckling learning to walk. But in a four-song encore, Lafourcade fled the dollhouse of her mind and shed the little-girl-lost persona that she’s rapidly outpacing.

Accompanying herself in a sensual cover of Maldita Vecindad’s “Kumbala,” then teaming up with gal-pal artist Ximena Sariñana on a boisterous version of “En El 2000,” she seemed all grown up and ready to rock.

reed.johnson@latimes.com