A key scene, appropriately, takes place inside a cinema, where Dylan and his girlfriend (Elle Fanning playing Sylvie Russo, a lightly fictionalised version of Dylan’s real-life paramour Suze Rotolo) are watching Bette Davis in Now, Voyager. Russo comments on Davis’ character being on a journey to find herself. “She didn’t find herself,” Dylan notes. “She just made herself into something different.”

It is something Dylan has been doing all his life. I once asked Joan Baez (elegantly portrayed in the film by Monica Barbaro as his lover, singing partner and early champion) how well she felt she knew Dylan. She smiled and said, quite seriously, “Bobby’s unknowable.”

If that’s what Baez thinks – a woman who has known him most of his adult life – what chance is there for any filmmaker or actor to get under his skin?

Writer and director James Mangold’s thoughtful movie doesn’t really attempt to solve Dylan the enigma as much as Dylan’s multifariousness. “You’re kind of an asshole, Bob,” Baez’s character notes at one point, which Dylan seems to accept as fair comment, an interesting aside being that both Baez and Dylan approved the script.

“Dylan was really helpful,” said Mangold, who also spoke to me at the screening. “He shared a lot of stuff from the inside about what he felt about so many people wanting things from him at such a young age.”

Mangold made the Oscar-winning 2005 Johnny Cash biopic Walk the Line starring Joaquin Phoenix, which took a conventional narrative form, locating the roots of Cash’s complexity in childhood trauma.

Adapting Elijah Wald’s 2015 book Dylan Goes Electric!, Mangold decided that he needed a different strategy for Dylan. “There was no real way to unlock Bob that was going to satisfy the kind of standard movie unlocking – like, Oh my God, he’s been hiding that secret, and now he’s spoken it, he’s released,” Mangold says.

“I think if there is any real secret, it is the burden and joy of something none of us can completely understand: how a young man can write so many of the greatest songs of all time, and become one of the greatest artists of the last 100 years, and secure that position before his 24th birthday.

“I don’t even know if Bob can explain it, and do we have to? Sometimes people are born with something, and there is no specific Freudian event of their genius that somehow is the cost. It’s actually that they’re touched in some ways.”

Chalamet is not the first actor to play this mercurial character. In Todd Haynes’ brilliant, experimental drama I’m Not There, he was portrayed by six actors, including Christian Bale, Heath Ledger and Richard Gere.

Ben Whishaw played Dylan as a rebellious poet channelling Arthur Rimbaud, black teenager Marcus Carl Franklin was cast as a young homeless busker and Cate Blanchett memorably evoked the lean, druggy, androgynous rocker who is effectively emerging as A Complete Unknown ends.

Blanchett’s performance has become a fan favourite, partly because it has an element of comedically edgy impersonation whilst embracing an androgyny that reflects Dylan’s near-universal appeal.

Dylan appeared as a minor character in Factory Girl (played by Hayden Christensen as “Billy Quinn”) and can be glimpsed onstage at the end of the Coen brothers’ folk drama Inside Llewellyn Davis.

Eddie Marsan offered an amusingly grizzled Dylan impersonation in a 2017 episode of Sky Arts’ Urban Myths, whilst John C. Reilly spoofed him in the comedy rockumentary Walk Hard, performing parody song Royal Jelly (“N’ the skinny scanty sylph trashed the apothecary diplomat / Inside the three-eyed monkey within inches of his toaster oven life.”)

But mostly Dylan has played himself. He has flitted in an inscrutable fashion through many documentaries, full of hipster scorn in D.A. Pennebaker’s cine-verite masterpiece Don’t Look Back, cut up to incomprehensibility in Dylan’s own Eat the Document, thoughtful in Martin Scorsese’s authoritative No Direction Home and mischievous in follow-up Rolling Thunder Revue.

He has portrayed his own alter-ego in his own movies, as folk singer Jack Fate in the sloppy but intermittently charming Masked and Anonymous (co-scripted by Dylan, under the pseudonym Sergei Petrov) and Renaldo in the amateurishly improvised Renaldo and Clara (directed by Dylan), in which Joan Baez also appears in white face makeup claiming to be Bob Dylan.

A 1978 review in the New York Times pertinently noted that “as an actor, Mr Dylan specialises in giving the simultaneous impressions that he isn’t really interested in acting and that he is always acting anyway.”

For a songwriter who opens up vast interior worlds in his work, Dylan never appears sincere on screen. He is a very flimsy presence in Sam Peckinpah’s elegiac Western Pat Garrett and Billy the Kid, for which he at least provided a classic soundtrack. He appears to be drunk all the way through the abysmal 80s rock romance Hearts of Fire.

Dylan’s love for movies permeates his work, even if his awkward screen presence suggests movies don’t always love him back. His accomplished amateur oil paintings often feature lovingly recreated scenes from old movies, whilst actors, film characters and whole lines of borrowed dialogue flicker through his songs, from name-checking Bette Davis in 1965’s Desolation Row to setting 1986 epic Brownsville Girl at a screening of Gregory Peck’s classic Western The Gunfighter.

Anita Ekberg, Brigitte Bardot, Sophia Loren, Peter O’Toole, Al Pacino and Marlon Brando are amongst the actors to have walk-on parts in Dylan lyrics, whilst Leonardo DiCaprio makes an incongruous appearance in Dylan’s fanciful 2012 retelling of Titanic, Tempest.

A fan website compiles 61 movies quoted in Dylan songs, a favourite apparently being The Maltese Falcon starring Humphrey Bogart, from which Dylan appropriated lines for three songs on 1985’s Empire Burlesque.

The Dylan portrayed by Chalamet in A Complete Unknown is at the start of his musical journey, but already a trickster and a fabulist. He drew heavily on Dylan’s 1960s press conferences. “He’s so confrontational in his attitude, sort of a wise-ass. When my own career took off, I was so obedient! Just to see how contrarian Dylan was at that age was so appealing to me.”

Dylan has offered words of encouragement, albeit via a typically ambiguous message on social media platform X. “Timmy’s a brilliant actor, so I’m sure he’s going to be completely believable as me. Or a younger me. Or some other me.”

Responded Chalamet: “That was hugely affirming.” The actor learned to perform 30 Dylan songs for the role. Despite Dylan requesting a script and agreeing to personal meetings, Mangold seems equally uncertain of the extent of his real interest, noting that the first thing Dylan asked him was, “So what’s this movie about?” Making his own inquiries, Elijah Wald, author of the source material, was told “Dylan doesn’t read about Dylan.”

For Mangold, it was vital that Chalamet and all his actors playing real people should have the freedom to bring their own characters to the role. “Timothee’s exceptionally bright, exceptionally logical, focused and verbal and articulate. There’s a lot I felt he could burrow into with this character. You’re playing a real person but if you want a perfect representation, we can actually watch footage of the real person …”

A Complete Unknown succeeds because it offers a visceral, entertaining glimpse into another side of Bob Dylan, rather than attempting a definitive portrait. “Who’s Bob Dylan?” as the man himself said at a press conference in 1986. “I’m only Bob Dylan when I have to be Bob Dylan. Most of the time I can just be myself.” Whoever that is.

A Complete Unknown is in cinemas from Thursday January 23