The path from popstar to Hollywood mogul is a road well travelled. Some – the Justin Timberlakes and Jennifer Lopezes of the world – have made the trajectory look effortless. Others, less so. Musical triumphs aside, the likes of Rihanna, Mariah Carey and Madonna have found the silver screen to be a harder nut to crack. The latter even tried – unsuccessfully – to get her 1979 indie flick A Certain Sacrifice banned from release.

Stefani Germanotta, a.k.a Lady Gaga, is perhaps better placed to carve a career in the acting world. Thanks to her 10-year tenure as her dramatic alter ego, Gaga is as much a performer as she is a musician. Her dominance on the stage has seen her compared to the likes of Madonna and David Bowie, with each performance a new iteration of her multi-layered character.

Indeed, despite early indications that she was destined for musical stardom (she started playing the piano aged four and writing songs aged 11), the young Gaga sought a career on the silver screen. It was acting that led her to a life on stage, and is perhaps what has most informed her flamboyant on-stage persona.

“When I was 19 years old, I told my parents I was dropping out of school and I was dragging my piano around New York City banging on doors so that I could perform,” she recalls. “I already knew then that I would be Lady Gaga. I was even lying, pretending to be my own manager so I could get the 10pm slot.”

This April, Gaga’s debut single Just Dance, which shot her to stardom in mid-2008 at the peak of the financial crash, marked its 10th anniversary. With six Grammy Awards, three Brit Awards, and multiple best-selling singles behind her, Gaga can be characterised as nothing less than an astonishing success. With her on-stage theatrics, wild costumes and exuberant persona, the pop phenomenon has developed a legion of quasi-fanatical fans and a penchant for staging outlandish red-carpet moments.

Meat dresses, madcap millinery and a loyal legion of Little Monsters (her fans) have gone on to define the singer we know today. In many ways, she has been the archetypal pop star of her era – a talented singer-songwriter who seemed to revel in the performative nature of the world of show-business.

But as recently as 2014, a noticeable change overcame Gaga – the public began, bit by bit, to see the real Germanotta come to the fore. That year saw the release of her album Artpop, which was perhaps the least well received of her recordings. The subsequent album, Joanne, released in 2016 and named after a maternal aunt, encapsulated the modern era of Gaga; it stripped back the oversized hair-dos and outrageous outfits to give fans a glimpse of the woman behind the star.

It is arguably this contemporary, soul-baring example of the once alien pop superstar that formed the basis for her character, Ally, in Bradley Cooper’s directorial debut A Star Is Born. The fourth version of the film – which debuted in 1937 and was perhaps most famously made into a rock musical in 1976, starring Kris Kristofferson and Barbra Streisand – follows the love story of country musician Jackson Maine (Cooper) and struggling singer Ally (Gaga), who has all but given up on her dreams. It’s not a feeling that the singer is familiar with.

“I heard the word ‘No’ a lot earlier in my career, but I never gave up,” she says. “That’s the biggest difference between me and Ally. Ally has completely given up and she does not believe in herself. She does not believe she’s beautiful and she does not believe she has what it takes. Once I had a record executive suggest that I get a nose job before my first single came out and before we shot the video. But I said no. They also wanted to give my songs to other girls or girl groups. They didn’t want it to be me; I just had to hold onto my music for dear life.”

Her latest project, however, has seen her pass the mantel – or microphone, as it were – to her co-star and director, Cooper. A man more famed for comedy portrayals (The Hangover), black comedies (American Hustle, Silver Linings Playbook) and war biopics (American Sniper), Cooper seemed the more incongruous of the pair when it came to filling the dual musical shoes of Kristofferson and Streisand. Not that that stopped him; the actor learned to play the guitar, worked with a vocal coach for a year and a half and ended up writing three of the songs featured in the film. “All because of Gaga,” he said in an interview with Vogue. “She really gave me the confidence.”

Indeed, at Gaga’s insistence, every performance featured in the film was recorded live. With the cameras rolling, Cooper took to the stage ahead of Willy Nelson at California’s country music festival Stagecoach, and even performed in front of 80,000 people at England’s own Glastonbury.

“I couldn’t believe how good he was,” Gaga admits. “I never ever knew that he could sing. We did a lot of harmonising, and there was something that just clicked when we were singing together.” Following a successful premiere at the Venice Film Festival in August, A Star Is Born is already causing an Academy Award buzz – but there will inevitably be critics expecting to label Gaga’s move from pop icon to movie star an inevitable misstep. Success or not, for the star herself this recent project will remain “one of the most fulfilling artistic experiences of my life, if not the most” – no small praise coming from such a chameleonic performer. There were times, however, when it seemed Gaga was shouldering the same burden of self-doubt as her character Ally.

“I was nervous, especially at the beginning, and of course you feel the pressure of living up to expectations when the stakes are pretty high, not just for yourself but for everyone involved,” she nods. “This was the first time I had to play in a film from beginning to end and I was scared. When an artist is moving into a new medium, if they have been studying and gestating like a petri dish for so long, it’s like an explosion when they finally come out.

“At one point, Bradley said something off-script to me, and I kept repeating that same line over and over again because I didn’t know what to do. And he said, ‘Are you okay? Do you feel like you need to cry?’ I cried for a second, and then I just threw the lines out the window. I still had them with me, but I was able to be in a more present conversation with him. It really taught me something about being an actor: you have to know the story that you’re going to tell, and you have to know the lines. But at the end of the day, you have to be as honest as possible in the moment.”

For all her misgivings, there’s always been an honest streak running through Gaga, however extroverted on the surface. Her philanthropic ventures and social activism have pointed to a person not wholly comfortable with her status as a music icon – and there’s an irony to her successes coming from a debut album entitled The Fame.

“Fame is a very unnatural thing,” she muses. “If you’re an artist, you have this intense relationship with your work and that’s what underlies everything. Then if you reach a certain point, everything changes around you and it’s not you who is changing but the people around you. I think artists need help adjusting to that because that’s often the biggest struggle you face, especially when you’re trying to keep evolving, not just in terms of your work but as an individual.”

An evolving persona has come to define Gaga – from budding singer-songwriter to pop superstar, fashion icon and now Hollywood actress – but for all her quirks, she’s only ever had one goal: “I just knew I wanted to be like myself, and no one else.” Mission accomplished.