Though she’s only halfway into her first beer of the night, it’s enough to loosen a confession from Mary Halvorson. The 26-year-old guitarist is becoming one of the most frequently spotted instrumentalists on the new music scene. She gigs in a variety of combos and formats at venues as upscale as the Iridium, where she’ll join the avantgarde composer Anthony Braxton for a week of shows in March as part of his “Ghost Trance” ensemble.

Yet Ms. Halvorson’s more intrepid listeners may find her under the radar at spots like the Asterisk Art Project, a collective loft space in an old Bushwick warehouse. Though steeped in jazz, Ms. Halvorson belongs to a generation of young musicians who pay about as much attention to genre definitions as they do borough lines. She plays guitar in a way that fractures conventions, restlessly inventing her own paradigms.

So, while having the inevitable conversation about influences, Ms. Halvorson dutifully name-checks demigods from Jimi Hendrix to Thelonious Monk, the pianist whose elliptical swerve may be a more profound resource for contemporary guitarists than most six-string legends. But, Ms. Halvorson admits, the first song she learned all the way through was also the most obvious: “Stairway to Heaven.”

“I think of myself as a guitar player,” she said, grinning only slightly sheepishly, as she perched on a barstool at the Parkside Lounge one recent evening. Ms. Halvorson was between sets nearby at the Stone, the Avenue C performance space whose February bookings she curated and where she will perform a few more times this month. “I’m not really concerned whether something is rock or jazz. I just want to play something that’s interesting to me.”

There’s a lot that interests Ms. Halvorson, who can be heard in many different modes. She can shred, as she does with bassist Trevor Dunn’s Trio Convulsant. She can play smooth, stately compositions that evoke some of Steely Dan’s elegant studio jazziness, as she does with Ted Reichmann’s combo, My Ears Are Bent. She’s a brisk thinker in improvisatory settings, unleashing a pointillistic spree of single notes as easily as she might concoct an unexpectedly beguiling melodic fragment — a knack she displayed recently in a duo with a former teacher, the innovative guitarist Joe Morris, at the Stone. And she sings, in a duo called People, with the drummer Kevin Shea, as well as in a separate pairing with her best friend, the viola player Jessica Pavone, whom she joins tonight for a set at the Stone.

“It’s definitely my most important project,” Ms. Halvorson said, recalling that, like many important things, the duo began as a kind of lark. One day while rehearsing, the women decided to each bring some lyrics to try out the next day. “We both ended up writing the same sort of thing. We can read each other’s minds. When we rehearse we’re usually checking out an episode of ‘The Sopranos,’ getting press stuff together for the next tour, and making dinner. It’s all the same thing. We’re very efficient.”

That spirit of playful nonchalance, along with the pair’s disarming alto voices, made the 2006 release “Prairies” (Lucky Kitchen) one of the year’s stealthier treats: the kind of CD fans would only buy from one of the women after a show, then play incessantly. The vibe shifts from bittersweet chamber reveries, paced by Ms. Pavone’s eloquent bowing and Ms. Halvorson’s heady scrambles, toward a particularly feminine humor. “Sometimes / when you are talking to me / I don’t hear / a thing that you say,” they sing on “Sometimes,” each syllable enunciated as if part of an exercise, harmonies rising like arched eyebrows.

Trumpeter Peter Evans, part of a new wave of exceptional players churning up the city’s jazz and improv circuit, recalls Ms. Halvorson as forming her sound early on. They met as teenagers at a weekend jazz program at the New England Conservatory in Boston, not far from the guitarist’s hometown of Brookline. “Mary sounded pretty much the same then as she does now,” Mr. Evans said, “which in a relatively straight-ahead jazz context was a little jarring. She would play these very pretty voicings and melodies, but her solos were really twisted and angular with huge interval leaps and jagged rhythms.”

Ms. Halvorson also wins praise from Mr. Morris, whose contemporaries began staking out their turf in the late 1970s and early ’80s. It’s been decades since the so-called “free improv” scene became codified, and he views Ms. Halvorson as part of a welcome arrival to what has been a male-dominated talent pool. “It’s about time a woman was given credit for making some new music on the guitar,” he said. “Mary has what it takes to be that woman.”

What’s refreshing is that gender is much less of an issue now. “When I was learning, no one would take me seriously because I was a girl,” Ms. Halvorson said. “If we’re going to get rid of the whole sexism problem, we need not to draw attention to those differences. That’s how I try to approach it. It’s going in the right direction.”