Hanging out with King Princess can feel like entering a time warp. At 21, she has the lush, broken voice of a hard-living lounge singer in a David Lynch film, and her music is similarly timeless: guitar-driven torch songs with lyrics sharpened by what sounds like a thousand years of love gone wrong. Listening to the yearning R&B swoon of “Prophet” — from King Princess’ debut album, “Cheap Queen” — you may imagine its maker as a sad-eyed recluse, one who wears her sorrow like armor. But in person — her birth name is Mikaela Straus — the singer comes off as a different kind of throwback: a bawdy, trash-talking caricature of old-school rock ’n’ roll excess.

In the time we spent together, I saw her mime masturbation after talking about how hot she thinks the singer Rosalía is (“She gave me a hug, and I was like, ‘You smell good.”); declare that if she were a man, she would “have a small [expletive], but it would work good”; and announce that she wants to give her girlfriend a cast of her vagina for their anniversary. In between takes at the video shoot for “Ohio” — a slow-burn ballad that descends into an unhinged rock jam — she asked several members of her team to smell her armpits (noting that the left one was noticeably more rank than the right) and talked colorful smack about other artists, esteemed music-industry institutions and an ex-girlfriend’s new girlfriend. “I want you to come to my apartment after this,” she said, staring me down during a moment of tenuous calm as her makeup artist sprayed a fine mist of glittering fuchsia across her cheekbone, “because I can tell it’s inconvenient for you.”

“There’s a bit of a ­Gallagher-y thing to it,” says the producer Mark Ronson, who released Straus’s debut on his own Zelig Records, referring to the fractious Gallagher brothers from Oasis. “She’s talking so much [expletive]. But when you’ve got that razor-sharp wit, you can get away with it.”

Ronson was there at the first of two deranged, joyous, sold-out January shows King Princess played at the Wiltern Theater in Los Angeles. “I’m glad Daddy came,” she would later say, using her pet name for the producer. As was the singer’s mother, Agnes Mullaney — petite, with a big smile and a mane of rock-girl hair. But backstage, it was a one-woman show. Straus was flushed and loose, cheerily announcing how drunk she was. After the film director Quinn Wilson, Straus’s girlfriend, arrived, they leaned up against the back of a couch with their arms around each other like high-school sweethearts. “So,” Straus said, staring at me playfully. “Did you like the show? Do you think I’m talented?”

The provocateur persona can seem a front, a superheroic avatar constructed to insulate Straus from a rough and sexist industry. Ronson notes that when they first met, Straus talked about gear on a level that was almost over his head. “She’s used to going into a writing session and people just condescending to her,” he says. “I think part of it was nerding out, and part of it was she needed me to know that she knew how to engineer and produce records.” But even if its roots are defensive, Straus’s attitude has evolved into something genuinely subversive. What she is crafting in King Princess, in and around all her bluster, is a potentially new kind of rock star, or at least an old kind of rock star for a new age.

Straus is “emotionally lesbian,” she says, but “culturally” a gay man: “Not really a woman, I’ve never been a woman. I’m a drag queen.” In other words, she’s a young, queer, female-presenting alpha, gleefully claiming a cultural patch of ground once mostly reserved for male artists. Watching her stalk the stage — as she did in Los Angeles that night — wearing a leather codpiece, smashing guitars into kick drums and making out with her girlfriend side-stage, you saw how last century’s notions of what transgression and decadence look like in a rock star can be reclaimed and repurposed. “The way she holds a guitar — no one has held a guitar and made it look that cool since the Strokes,” Ronson says.

The person pulling the persona’s strings is, Straus explains, the kind of obsessive kid who has been practicing her Grammy speech in the shower since elementary school. As both person and persona prepare to join Harry Styles for European dates this spring — as well as release a forthcoming dance E.P., a homage to Diana Ross and early Madonna, a break from what she calls her “sad lesbian” repertoire — it’s apparent that as magnetic as King Princess is, if she becomes a superstar, it will be because Mikaela Straus willed it.

“It’s gonna be an ‘I told you so’ moment,” she says. “I’m gonna be like, ‘What were you all waiting for?’”

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Straus all but grew up in a recording studio. “It was everything,” she says of Mission Sound, the Williamsburg spot her father founded in 1995 and still runs. “It looks like a spaceship,” she says. “I’m so horny for that. I just love gear and equipment.” As a kid, tucked away and playing with musical toys in that dark, womblike space, Straus could forget how isolated and friendless she was. The only child of divorced parents, a kid with “horrible authority issues,” Straus had good reasons to feel like an outsider. “I was confused why other people couldn’t understand that I just wasn’t a girl and I wasn’t a boy,” she says. “I was really confused as to what gender I was until … now. Until tomorrow.” Her future, though, seemed clear. “You know what’s not a fun person to be around at age 7, 8, 9?” she asks. “Someone who knows they’re going to be famous. That kid is challenging. I was a lot. I was brutal. I had a band in high school that I was brutal to, and I’m still that way, like James Brown — you get billed if you play wrong. That’s my vibe.”

At Avenues, a private school in Manhattan, Straus tried oral sex with boys (“I wasn’t a hit — they were like, ‘Please stop,.”) dressed super­feminine, “felt the most gender-dysphoric ever” and discovered she harbored a seething proletariat rage; she was the resentful financial-aid kid eating Chipotle while her friends took one another out for swanky Italian at Serafina. Thanks to Mission Sound, though, Straus knew how to recognize members of her particular rock ’n’ roll tribe: “It was cool people being silly, but on top of being silly and drinking and smoking and chilling, they were also there for a collective goal of making something.” And through her mother, who worked in fashion, Straus found her L.G.B.T.Q. community. “My mom was really incredible about the queer men that she surrounded me with,” she says. “I felt so connected to the humor and the lack of gender that these men embodied who lived through the ’80s. It was all about ball. It was all about drag” — in New York’s underground queer subcultures. “Everyone calls each other girl. Those things felt like home to me.”

Arielle Bobb-Willis for The New York Times

King Princess’ music reflects an ongoing conversation between those two worlds — the ecstatic rage of rock and the celebratory sadness of club culture. “That moment where you hear that music and you feel like moving your body, and on top of it you’re like, I think I’m gay,” she tells me. “It’s something all queer people share.” Ask her about her influences, and she brings up “Chelsea Hotel singers” like Leonard Cohen and Patti Smith, as well as “the Princes and the Freddie Mercurys and the Eltons and the Billie Holidays and the Tina Turners.” But she doesn’t write, she says, with a voice or face or body in mind — just chords and melodies, often at a piano. “I never start with lyrics.”

The “Cheap Queen” persona that gives form to those sounds — “evil, but fun when I’m fun” — traces back to high school, when Straus allowed the emotional “hell” she felt in middle school to harden into a weapon. The way she tells it, she bottled up all her adolescent bitterness to become a kind of sexual avenger, hooking up all over school, getting caught “all the time” and scoring an uncharacteristic A in advanced biology “because my teacher was so hot, I wanted her to love me.” Other kids, she says, called her “the lesbian witch,” and she developed the ability to talk them into giving her things, or else she just took them. “The boys wouldn’t [expletive] with me because I’d be like, ‘I will [expletive] your girlfriend,.” she says. “And I did. That was my power.” When Straus talks like this, it’s as if she’s flexing both for her audience — regaling you with fantasies of being late for basketball practice because you’re under the bleachers with the cute point guard — and for herself, as if she needs to revisit her own conquests. “I’ve always been somebody that’s wanted the attention of people that I love,” she says. “And always felt disappointed.”

Longing is key to Straus’s creative process. In high school, the singer developed “brutal crushes on all of my straight female friends.” As a wooing tactic, she would play the songs she wrote for them. It worked, so she kept doing it. King Princess’ 2018 E.P., “Make My Bed,” was written while Straus was enrolled in the music program at the University of Southern California. It features the wrenching “Talia,” about being haunted by an ex whose lipstick she can still taste, and her other early hit, “1950,” inspired by Patricia Highsmith’s story about ­lesbian love, “The Price of Salt.”

The album, “Cheap Queen,” is largely about Straus’s relationship with her ex-girlfriend, the actress Amandla Stenberg. (“I was like, ‘Bitch, date me,” Straus says. “That could have been the name of the album, and the deluxe is ‘But it didn’t work out.”) As a songwriter, Straus is doing what straight people have done throughout the history of pop: making her pain universal. “My music is queer because I’m queer,” she says. “But queer artist is not a category. You can’t make a playlist for queer artists because they’re not all the same. I don’t want to be put in the same category as a lot of these hos. I don’t like that. I want to compete with straight people. I want to fight some straight bitch to the death: Who can write a better song? I don’t want to be compared to just gay people.”

“Hey, Lizzo,” Straus said into her iPhone, waving at the screen. We were driving from the bar in Silverlake where she shot the “Ohio” video toward her Hollywood apartment, and she was Face­Timing with Wilson, who is Lizzo’s creative director, to find out when Grammy rehearsals would end so they could meet up. Straus was wearing a bucket hat, track pants and a cherry ­red sports bra from the AVN awards, the so-called Oscars of porn, which she had recently attended. As she hung up, “Gold Dust Woman,” by Fleetwood Mac, came on the radio. “Cocaine affects how you register sound,” Straus remarked. “When you listen to late-’70s Fleetwood Mac, the later stuff especially, they call it a Lindsey Buckingham mix. It’s all top-end because when you’re on uppers, top-end makes you happy.”

Arielle Bobb-Willis for The New York Times

Straus’s egghead rock-kid brain is a roiling engine filled with industry lore and is constantly running, like spyware, in the back of her mind. “I don’t think there’s any place where I feel more comfortable or in control than in the studio,” she says. Ronson compares her skill set — songwriting, performing, production, engineering, facility with studio gear — to that of mad-scientist prodigies like Jack White. But Straus’s confidence in this arena also has the perverse effect of feeding her often-combative relationship with the music industry. She resents how little people ask her about producing her own music, how they “assume Mark produces me.” (He does not.) She longs to be a name producer herself, especially for other female artists. “People complain that women don’t have power,” she says, “and I’m like, ‘Well, the power comes from knowing how to use the computer.” She said “horrible, horrible things” while watching the Grammys from home and dealt with the envy they inspired by Insta­gramming photos of Britney Spears in cutoff denim shorts, which, Straus says, is what she’ll wear when she’s cleaning up next year.

“My jealousy comes from two places,” she says. “One, wanting that to be me, and two, wanting the world to be better, wanting us to be better, and feeling like I could do it.”

Getting this far, this quickly, has already taken a toll. By way of measures she has put in place for maintaining mental wellness, Straus mentions therapy with her manager; “things other than music,” like playing video games; and making collage art in Photoshop. “This is of Gypsy Rose Blanchard,” she says, showing me an Instagram piece featuring the now-incarcerated Blanchard, a victim of Munchausen-by-proxy abuse who persuaded her boyfriend to murder her mother. “I think the fact that I’m worried is a good sign,” Straus says of her mental health. “If I wasn’t worried, I’d be a psycho. If you don’t actively fight being a narcissist in this career, you become a monster.”

Given that her version of self-care is collaging about murderous children, it was surprising to find Straus’s apartment, off a leafy block in Hollywood, so airy and serene. “Yeah, I know,” she said, unlocking the door and tossing her keys on the coffee table. “It’s been really calm lately because I’ve been having adult conversations with myself. Like, Mikaela, this apartment needs to be nicer.” She took a seat and cracked open a yerba mate. “And then I made it nicer.” She hadn’t even killed the houseplants Wilson got her.

“I’m so excited,” she said, grinning as she turned on her “very advanced speaker system” — a portable Bose — and cued up the tracks from her new dance E.P. “I just realized how much of a sensibility I have for making fast music.” She looked around for her Juul charger. “What I’ve been making is so meaningful and important to me, but it’s also so reflective of a very specific side of my influences. There’s this other part of me that has fun. The lyrics are still sad — it’s all about being heartbroken — but it’s about being heartbroken at the club.”

To her left was a giant gig poster from 2009, when the ingenious South Bronx no-wave group ESG opened for Yeah Yeah Yeahs at Radio City Music Hall. Behind her was a John Waters print (“my prized possession”), and scattered throughout the light-filled apartment were assorted mini-shrines to Cate Blanchett. “I’ll just play you one more,” she said, scrolling through tracks on her laptop. For the moment, at least, she was barely recognizable as the Cheap Queen. She was just a 21-year-old music fan, surrounded by talismans of her heroes, so full of love for the songs she’d been making that she could barely contain the joy in her athleisure-wear-covered limbs. “Or I guess I’ll play you two more,” she said. “It’s a new side of me that isn’t so sad.”

Lizzy Goodman is a journalist and the author of “Meet Me in the Bathroom,” an oral history of music in New York City from 2001-11. She last wrote for the magazine about the U.S. women’s national soccer team and pay equality. Arielle Bobb-Willis is a photographer from New York who was recently featured in Aperture’s “The New Black Vanguard.” This is her first assignment for the magazine.

Stylist: Sean Knight. Hair: Jerome Terry. Makeup: Sara Tagaloa.

Additional design and development by Jacky Myint.