Jazz guitarist Mary Halvorson’s career features some odd cross-genre ventures, from the roiling rock trio People to fellow six-string maverick Marc Ribot’s jagged Young Philadelphians, a band that grooves on Philly soul and covers disco classics.

Halvorson’s own projects include solo jazz standards, a composed octet and power trio Thumbscrew. When she wanted to write lyrics for another vocalist in her new quintet Code Girl, reflecting on favorite singer/composers as eclectic as Robert Wyatt, Elliott Smith and Fiona Apple, accessibility wasn’t her goal.

“It’s funny, because I don’t really think about things like that,” Halvorson, 37, says. “I kinda had no idea what this [group] would come out like. … But it’s definitely not a jazz vocal sound.”

It’s not like the Brookline native needs a profile boost in the wake of DownBeat’s 2017 Critics’ Poll, which named Halvorson the top guitarist over the likes of Bill Frisell, Pat Metheny and John Scofield. “It was something of a shock, and it feels amazing to be alongside some of my favorite guitarists,” she says. “I’m really thankful for stuff like that because it’s an opportunity for people to check out your music.”

Her music can be harder to wrap one’s ears around. Unlike those other players, easily identifiable by cushiony processed tones, Halvorson favors a prickly, clean hollow-body sound over the cyclical blur and wobble of her effects pedals, filling a void between early jazz idol Wes Montgomery and noise-rockers like Sonic Youth.

“The beauty of the guitar is [that] there’s so much you can do with it, with sound alone,” Halvorson says, citing late exposure to jazz as a reason that she’s probably more influenced by rock and folk. “The guitar lends itself to shape-shifting.”

Her first instrument was the violin, but she didn’t enjoy playing in orchestras. At age 11, Halvorson discovered Jimi Hendrix: “I was more interested in that, and something about the excitement and improvisational energy coming from Hendrix made me decide to take up the guitar.”

Halvorson didn’t embrace jazz by design. Her parents bought a cheap Stratocaster like Hendrix’s guitar and supported lessons. She ended up studying with local jazz player Issi Rozen and revisited her dad’s record collection to absorb Miles Davis, John Coltrane and Thelonious Monk, even if the melodies hooked her more than improvisations—at first. “Like any music I’ve grown to love, it often takes time,” Halvorson says. “The more you learn about it, the more interesting it gets.”

From Brookline High, she headed to Wesleyan University to study biology but came under the spell of Anthony Braxton, a revered saxophonist/composer in avant-garde circles who taught there. “It didn’t occur to me when I was in high school or starting college that music could be a career for me,” Halvorson says. “Maybe I’m just a practical person. It didn’t seem like a practical thing to do.”

Braxton encouraged Halvorson to find her own voice, be open-minded and not be afraid to make mistakes, Halvorson says, adding, “At some point, I just dropped my science courses.” Lessons with guitarist Joe Morris had a similar effect; he played standup bass to her guitar, improvising beyond the lure of imitation.

Female role models, particularly on guitar, were hard to find when she started—but not now. “I have a lot of female students, and I see a shift in momentum,” Halvorson says. “It’s not uncommon for me to play in bands where women outnumber men.”

For Code Girl, she drafted Amirtha Kidambi, a classically trained vocalist of South Indian heritage. Bassist Michael Formanek and drummer Tomas Fujiwara (both of Thumbscrew) and trumpeter Ambrose Akinmusire round out the group, whose eponymous debut drops March 30. Code Girl plays two of Halvorson’s former teenage haunts, the Regattabar (where Adam O’Farrill subs on trumpet) on March 29 and the Newport Jazz Festival on Aug. 4.

“Because I’m not a poet or lyricist, I didn’t feel impeded by any pre-existing technique,” says Halvorson, who wrote largely abstract lyrics and formed music around them, accommodating irregular rhythms to set up Kidambi’s phrasing with eclectic art-song freedom. “It was pure experimentation, which was a lot of fun.” ◆

Mary Halvorson’s Code Girl plays the Regattabar on March 29.

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