Early in her career, not long after she had clawed her way out of small-town New Jersey poverty, the pop singer Halsey received an enthusiastic communication from her record company. The label was brokering her first major interview, with Rolling Stone magazine. The plan was for the then 21-year-old to accompany a journalist “on a romantic boat ride” around Manhattan.

“F***, no,” was Halsey’s response. “I’m not going on a sailboat. I f***ing hate boats. I’m not going to do that.” Instead, she and the reporter met in Central Park, where Halsey sipped Veuve Clicquot champagne from a red “solo” cup.

Champagne from a solo cup – the vessel of choice for teen drinkers across America – gets to the essence of Ashley Nicolette Frangipane. As Halsey, her music is sparkling, glamorous and easily imbibed – her songs are suggestive of an all-night party of which your parents might not approve. And yet hits such as “New Americana”, “Graveyard”, and even her biggest smash, the 2018 Billboard No 1 “Without Me”, give off a weird glimmer. They are shiny and accessible, though they cast a wonky shadow. This marks her as a fascinating anomaly – an outsider at the heart of the pop pantheon and a major-label artist who doesn’t play the game, even if the game involves going for a pleasant boat journey with a journalist.

Halsey cuts an intriguing figure in a crowded field. Listening to her music is a bit like going to a pop concert and ending up in a mosh-pit. She can radiate a nightmarish effervescence reminiscent of Boys For Pele-era Tori Amos (“Graveyard”) as easily as she can deliver an old-school belter with a thorn in its side (“Eyes Closed”). There is the sense that just beneath the surface, a mohawk-sporting rocker is itching to break free. “Experiment On Me”, for instance – from the Birds of Prey soundtrack – is audibly inspired by her years as a teen punk raised on All Time Low and Panic! At the Disco.

But although she has released three albums – with a fourth, If I Can’t Have Love, I Want Power – due on Friday, Halsey still feels like an artist who is yet to reach the iconic status of, say, Taylor Swift, Ariana Grande or Billie Eilish. Though she is more than worthy, it’s hard to imagine her as enough of a household name to grace the cover of Vogue just yet.

Then again, the 26-year-old – who identifies as non-binary and favours the interchangeable use of the pronouns “she” and “they” – is not set on success at any cost. Her 2015 debut Badlands was a snarling work in progress from a young woman growing into her star-power, while 2017’s Hopeless Fountain Kingdom saw her dipping a toe into the pop-industrial complex and teaming up with star producers. A raft of starry co-writers similarly featured on 2020’s Manic – and yet that record was far rawer and saw Halsey chronicling her mental health struggles. By their third LP, many in her position would have zigged towards the mainstream. Halsey instead zagged into her own heart of darkness.

Halsey’s not just a star but a maverick, too. That point is forcibly communicated on If I Can’t Have Love, I Want Power. Rather than being just another break-up LP or lockdown meditation, it’s styled as a visceral concept record “about the joys and horrors of pregnancy and childbirth”. Joy and horror are certainly front and centre in the cover art, which depicts the (then-pregnant) singer on an imposing throne straight from George RR Martin’s fantasy books, with one breast exposed, holding a baby. The image is unsettling – Halsey’s features are frozen in an expression of chilling elusiveness – yet playful, as if channeling a Tudor painting.

The artwork’s unveiling comes on the heels of an equally sensational Instagram post. In it, Halsey shared images of her postpartum belly following the birth of her baby, Ender Ridley, with her boyfriend, the screenwriter Alev Aydin.

“It was very important to me that the cover art conveyed the sentiment of my journey over the past few months,” Halsey wrote. “This cover image celebrates pregnant and postpartum bodies as something beautiful, to be admired. We have a long way to go with eradicating the social stigma around bodies and breastfeeding.”

The other major talking point around the new LP is the fact it is produced by Trent Reznor and Atticus Ross of Nine Inch Nails. Nine Inch Nails are, of course, massively influential. Their synth-powered industrial rock has informed everyone from Muse to Billie Eilish.

That isn’t to overstate their potential impact on Halsey. There is a toxic trope in pop of male producers deigning to “shape” a female artist. It continues to this day, with Lorde recently pointing out that, though she works with Jack Antonoff, she isn’t part of a “stable” of Antonoff stars. Nor, by the same token, is Halsey a muse to Trent Reznor.

That being said, Reznor has always selected his collaborators with extreme care. Anyone familiar with both his music and Halsey’s will appreciate that they are kindred spirits. Nine Inch Nails’ music is rooted in a sense of being an outsider. And so, too, is Halsey’s – her breakthrough 2015 single “New Americana” is a riotous celebration of not fitting in. Like Reznor, she refuses to slot neatly into any of the record industry’s pre-assigned boxes.

She grew up in challenging circumstances in suburban New Jersey. Her mixed-race parents – her father is Black, her mother white – were both teenagers when she was born and had recently dropped out of university.

“We moved wherever the jobs or cheap apartments were,” Halsey told Billboard in 2015, explaining that by the time she was 13 she’d attended six schools. “I’m used to ­packing up and leaving, to condensing myself into a digestible version because people don’t have much time to get to know me.”

Halsey has been openly bisexual throughout her time in the spotlight. She was upfront with fans from the outset: in the video to her 2014 debut single, “Ghost”, for instance, she partners with both men and women. She had by that point long since fallen out with her mother and father, who threw her out of the house when she quit school and was generally disruptive (they have since reconciled).

There followed a bohemian existence of couch-surfing in New Jersey and Brooklyn. She drank, and smoked too much weed. Sometimes there was barely enough money left over for food. This was the point in her life when she started to cultivate the alter ego of a pop star. “Halsey” is an anagram of Ashley. Her stage name was also inspired by Halsey Street subway stop, near the post-industrial loft in Brooklyn that she briefly called home.

“I remember one time I had $9 in my bank account,” she said, recalling her years of impoverishment to Rolling Stone, “and bought a four-pack of Red Bull and used it to stay up overnight over the course of two or three days, because it was less dangerous to not sleep than it was to sleep somewhere random and maybe get raped or kidnapped.”

She was furthermore coming to terms with her bipolar disorder – a condition she unpacked on Manic. She was diagnosed aged 17 (and later discovered her mother was also bipolar). This followed an attempt to take her own life, in which she overdosed on over-the-counter painkillers.

These were not circumstances conducive to a blockbusting music career. However, her life had a Sliding Doors moment when she struck up a conversation with a music executive at a party at a Holiday Inn in Newark.

She played him a “demo” of “Ghost” – in reality, a fragment of the chorus taped on her phone. Struck by her voice and by her pluck, he put her in touch with friends of friends. A few weeks later she was in a professional studio for the first time recording this dirge about an ex lost to heroin. She uploaded “Ghost” to SoundCloud and within five hours was receiving emails from a scrum of major labels.

Despite being clearly unconventional in her music and outlook, it is undeniable that Halsey possesses many traditional pop-star attributes. Her cheekbones are photoshoot-ready. And her dusky singing voice, melancholic but with a punch, sounds perfect on radio or a streaming service’s “new music” playlist.

Inevitably, she was accused of being the worst thing anyone in music could be: an industry plant. The cynicism around her moved up a notch when she was quoted in The New York Times as describing herself as “tri-bi” – bisexual, bipolar and biracial.

Halsey insisted that she had never used this reductive term. “The funniest thing is that the biggest battle that I’ve had to overcome in my career was not being bisexual, was not being biracial, was not being bipolar,” she said. “It was everybody thinking that I was exploiting those things.”

There has been pushback for other reasons, too. She was criticised for using transphobic slurs in pre-stardom Tweets (after having her make-up done in 2009, she said she “looked like a hot trani mess”). She has gone viral in the negative sense for pulling underage fans up on stage and kissing them, once or twice allegedly without their consent. And she has been attacked for obsessing over negative social media comments and encouraging pile-ons by her army of “stans”.

Whatever is to be made of these accusations, Halsey is clearly a complex figure and hard to pigeonhole. To fans, she represents an agent of chaos in an often slick and predictable entertainment industry. Her achievements are nonetheless substantial. She has sold more than a million albums and notched up 6 billion streams. Manic, despite sometimes dismissive reviews, charted at No 2 in the US and No 6 in the UK. She’s a phenomenon – but one with the potential to burn even brighter.

Success did not bring an end to Halsey’s heartache, however. She miscarried on stage in 2015 and was later diagnosed with endometriosis. “The sensation of looking a couple hundred teenagers in the face while you’re bleeding through your clothes and still having to do the show, and realising in that moment,” she wrote on Instagram, explaining her decision to put her career temporarily on hold while seeking medical intervention for the condition.

“I never want to make that choice ever again of doing what I love or not being able to because of this disease. So I put my foot down and got really aggressive about seeking treatment, and I had surgery about a year ago and I feel a lot better.”

Now, as she and her partner adjust to first-time parenthood, she is about to release potentially her biggest record to date. Judging by the snippets of new music playing over the “trailer” for the record, she will be bringing the fireworks. “Don’t wait for me… it’s not a happy ending,” she sings against a crashing tumult of strings, sounding like Celine Dion in a techno-punk remake of “My Heart Will Go On”. It is certainly receiving a bombastic rollout, with the album to be accompanied by a 60-minute IMAX film of the same name (directed by Colin Tilley, who oversaw the video to “Without Me”).

Pop is today blessed with a galaxy of luminescent talents. What’s missing is an outsider prepared to storm the battlements and bring some glorious weirdness. Halsey could very well be that figure. Pop’s darkest star may finally have their opportunity to shine.

‘If I Can’t Have Love, I Want Power’ is released Friday 27 August. The film of the same name will screen at selected IMAX cinemas on Thursday 26 August