Timothee Chalamet sings Bob Dylan in A Complete Unknown trailer

Timothee Chalamet is seen singing as Bob Dylan in the first trailer for a new film in which he plays the folk-rock legend as a young man.

The biopic, titled A Complete Unknown, has been given a December release date for the US - a prime time to be in contention for next year's Oscars.

The film starts with Chalamet's Dylan arriving in Greenwich Village, New York, in 1961 with his acoustic guitar in his hand and $12 in his pocket, and ends after he controversially "went electric" four years later.

In the trailer, Chalamet is seen with Dylan's distinctive tousled hair, performing his 1963 classic A Hard Rain’s a‐Gonna Fall.

Director James Mangold - who also made Oscar-winning 2005 Johnny Cash biopic Walk the Line - said the actor had been "brave enough to stand out there and make himself vulnerable, throwing himself at this".

His vocals generally went down well on social media.

"Timmy doing his own singing AND PULLING IT OFF. Color me impressed," wrote one user on X.

"Did Timothee sing the songs himself? If yes then incredible, it sounds so much like Dylan. Wow," another said.

However, some were less impressed. "That singing ain’t it," one wrote.

Mangold told Rolling Stone the actors did their own singing - with the proviso that he could fix anything necessary in post-production.

"You want everyone putting everything on the line every moment," he said. "But it’s not [like] if one of our actors hit a bad note, I don’t have an alternative take or the ability to replace that one beat.

"If Timmy’s brave enough to stand out there and make himself vulnerable, throwing himself at this, I should be brave enough to stand behind the camera and shoot.

"And Timmy was a partner in this. He very much wanted to. And the multiple years of preparation that we had on this movie because of false starts with Covid and stuff meant that Timmy really had a kind of incubation as a musician that was years in happening."

A Complete Unknown follows Dylan's rise to fame, as the artist who revolutionised American music with his personal and poetic folk-rock songs.

Mangold said he was attracted to "this idea of a talent like Bob, so vexing, so provocative, so filled with fiction and fact".

"This idea of this incredible, artistic character landing in New York with $12 in his pocket - trying to thread the needle of how one goes from there to there is so interesting to me," he said.

The director got the blessing of the real Dylan, who is listed as an executive producer.

Chalamet has already starred in two of the biggest films of the past year - Wonka and Dune: Part Two.

The 28-year-old could now be in contention for his second Oscar nomination, after being nominated for his breakthrough film, Call Me by Your Name, in 2018.

The cast of A Complete Unknown also includes Edward Norton as folk legend Pete Seeger and Monica Barbaro as singer Joan Baez.

Dylan has previously been played on screen by Christian Bale, Cate Blanchett, Richard Gere, Heath Ledger, Ben Whishaw and Marcus Carl Franklin - all in the 2007 film I'm Not There.