Billed as a conversation with Jeremy Allen White, and promising “a special guest”, there was very little surprise when Bruce Springsteen arrived on the small stage at Spotify’s London offices on Tuesday evening. The actor and the rock star walked on separately, but to the same clip of entrance music: the opening lines of Atlantic City, from Springsteen’s 1982 album Nebraska.

It is, after all, the making of this record that provides the focus for Scott Cooper’s new film Deliver Me From Nowhere, that sees White cast as Springsteen at a critical moment in the singer’s life and career. Much of the evening’s conversation, steered by Edith Bowman, focused on the intricate process of becoming Bruce, and the unavoidable peculiarity of art meeting life.

Springsteen – throughout, a portrait of reptilian poise – spoke of first sighting White during a sound check at Wembley Stadium, in the summer of 2024. “Jeremy was wearing all white, so he was easy to spot,” he recalled. “I just kind of waved him to the stage and we said hi.” White was already well steeped in Springsteen’s music, had watched hours of concert footage, and read a glut of interviews and biographies. The Wembley show was an opportunity for a greater understanding of Springsteen as a live performer, and to discuss some of the specifics of the Nebraska period with the singer himself. Springsteen recalled bracing himself for an interrogation that did not come: “I thought this guy is really gonna be interested in me …” he said. In the end, however, “Jeremy was so prepared, he really asked very few questions.”

It was an intimidating role to take on, White said. He referred repeatedly to the sheer weight of Springsteen information available, the amount of learning he had to take on, and spoke of “the pressure I was putting on myself. Bruce called it ‘focus’. I called it ‘anxiety that hardened, maybe, into focus.’”

For all the learning he undertook, it was through the music itself that he really connected to the part. “A lot of my energy was going into the musical component of the film,” he said. “[Scott] wanted me to sing and play the guitar, and I said, ‘I don’t do those things … are you sure?’” Cooper was adamant. White duly recorded his own versions of Springsteen’s songs. “I remember being in Nashville, at RCA [studio], in the booth, singing Nebraska, and finding some confidence … feeling close to Bruce, in a way,” he said. “When you’re reading a great script, your job is very easy,” he said. “And when you’re reading Bruce’s lyrics, it’s the same. Everything’s right there.”

Springsteen also sent White a 1955 Gibson J-200 – the closest he could find to the guitar used for Nebraska, and “just about the nicest guitar you can learn on,” White says. He began guitar lessons, via Zoom, with session player JD Simo. “Hey, I’m so excited to learn guitar with you,” White recalled saying on their first meeting. “We don’t have time to learn the guitar,” Simo replied. “We have time to learn these five Bruce songs.”

Springsteen’s own feelings about the film were initially less complicated. “I figured I’m 76 years old, I don’t really care what the fuck I do any more,” he said. “Yeah, go ahead. At my age you take more risks, in your work and in your life in general.” It helped that Cooper was “a real blue-collar film-maker” making “the kind of film I would be interested in,” he said. “Not your standard musical biopic, but more of a character-driven drama with music.”

As the project gathered pace, it perhaps became stranger. Springsteen visited the set often, apologising to White each time he made an appearance. “It’s gotta be really weird with the guy’s stupid ass standing there,” he said. But he liked what he saw: “I’ve said this before, but I kept thinking ‘Damn, when did I get that good-looking?’” In the seat beside him, White wags his finger and shakes his head.

Springsteen had few doubts about White’s casting; he knew that the actor was equipped to portray the most introspective time in his recording career. “I’d watched The Bear, and how the camera followed his internal life,” he said. “And if you see him in a film, it’s a cliche, but he’s a rock star.”

When he first saw White playing him, he was struck by the actor’s approach. “His performance was totally from the inside out, not just picking elements and wearing them like clothes,” he said. “It’s a non-imitative performance, but somehow it greatly relates to my story and myself.” He saw it as something akin to his own approach to songwriting – to writing about people whose lives differ so greatly from his own. “You have to find the part of them that is part of you.”

More unsettling was the way the film forced him to revisit difficult periods in his own life. The recreation of his grandparents’ home in Freehold, New Jersey – a house he once described as “the greatest and saddest sanctuary I’ve ever known” was uncanny; Springsteen described how often he visited the home in his dreams. “So, to be in that house again … it was quite a miracle, and quite wonderful.”

Similarly, it was “a very powerful thing” to see Stephen Graham as his father – capturing his volatile early years, when he suffered undiagnosed mental health issues and drank heavily, and the vulnerability and sweetness of his later years.

Springsteen told of watching an early screening in the company of his sister, who held his hand throughout. Just a year younger than her brother, “she remembered everything”. At the end, she turned to him and said: “Isn’t it wonderful that we have that?”

There was an echo, perhaps, of the feeling Springsteen hopes to give his own audiences through his live shows. “You create an ideal world for three hours,” he told the small crowd before him last night. “It’s not a fantasy world. It’s a very credible world. It has all the wonderful and terrible parts of life … But hopefully there’s an element of transcendence that my audience takes with them. And hopefully it stays with them for as long as they need it.”

• Legend: The Bruce Springsteen Story, presented by Laura Barton is available on BBC Sounds