Ryan Gosling and Emma Stone prove to be the perfect pairing again – this time in La La Land

It is strange to think that the original plan for La La Land involved Miles Teller and Emma Watson in the lead roles, because this love letter to Hollywood and the golden age of the musical seems tailor-made for Ryan Gosling and Emma Stone, its eventual stars.

She is fresh off Broadway hit Cabaret, while he spent his early years singing and songwriting. This is their third pairing, after Crazy, Stupid, Love and Gangster Squad.

“Music has always been a part of my life,” says Gosling, “though it’s never been quite as highbrow as this.”

Intriguingly, the two stars came to this Los Angeles-set love story from different angles. “My musical movie knowledge was basically Singin’ In The Rain and Disney animated movies,” says 28-year-old Stone. “I mostly loved musicals on stage.”

Gosling, 36, was more inspired by song-and-dance movies.

“I didn’t really have a lot of knowledge of stage musicals, so, for me, this was right up my alley, because I guess the ones I had grown up on were musicals made for film,” he says.

Written and directed by Whiplash’s Damien Chazelle, La La Land is already shaping up to be the film to beat during the coming awards season. Since its premiere at the Venice Film Festival in September, where Stone received the Volpi Cup for Best Actress, it has been enchanting audiences. It is the frontrunner in the Golden Globes on January 8, with nominations in seven categories, and already the hot favourite to sweep the Oscars next year.

It is not hard to see why. Rather like the 2012 surprise Oscar winner The Artist, it is a film about Hollywood and big dreams. “I relate to what it feels like to really want something to work out and for it not to – that feeling of rejection,” says Stone, who plays Mia, an aspiring actress whose life in Los Angeles revolves around work in a coffee shop on a studio backlot and gruelling round of auditions.

Everything changes, however, when she meets Gosling’s character, Sebastian, a jazz pianist forced to tinkle the ivories in a restaurant to make ends meet.

“He’s [playing] background music,” says Gosling. “[He’s] been around for a long time, trying to make it happen, having a hard time accepting that jazz is never going to be on the top of the charts again – and is trying to find a way to make a living but also not compromise everything he has worked for.”

As the pair fight, flirt and fall in love, the story takes Gosling and Stone on a beautifully crafted musical song-and-dance odyssey.

“It was a tall order for both of them,” says Chazelle. “It’s part of why musicals are scary. There are so many added layers of stuff you have to do, just on a basic practical level within this genre. They had to sing, they had to dance, Ryan had to learn piano … and that’s all on top of the more day-to-day character work that they would do on any movie.”

For Gosling, whose prior dance skills were largely restricted to busting out 1990s hip-hop moves when he was a child, the experience proved particularly tricky. “I thought I had it in the bag because I had mastered ‘the running man’ [dance move] from Who Framed Roger Rabbit” he jokes.

“But it turns out that tap and jazz are a little more difficult than that. It was a lot like that movie Cutting Edge, when the hockey player has to learn how to figure-skate – it doesn’t translate.”

Fortunately, he and Stone had some expert dance tuition, in the shape of professionals from the popular show Dancing With The Stars.

“We learnt to ballroom dance,” says Stone. “They’re used to teaching people who don’t really know what they’re doing to dance quickly. They were amazing.”

Inspiration came from other sources, too. They visited Patricia Ward Kelly, widow of legendary Singin’ In The Rain star Gene Kelly, and combed through the actor-dancer’s archives.

For Gosling, one of the real pleasures of the film was learning about Kelly and fellow dancers Fred Astaire and Ginger Rogers.

“I’d always liked Gene Kelly and I’d always heard he was the more visceral, masculine version of all of the dancers,” he says. “But when you watch Fred’s stuff, he’s very antagonistic. He’s breaking glasses on the bar or doing a tap-dancing step that sounds like machine gunfire and it scares everybody off. There’s something really aggressive about what he did … I’d never heard that about him.”

If Gosling and Stone aren’t quite as athletic as Fred and Ginger, their moves are still more than impressive – not least because Chazelle shot long takes.

“It felt like live theatre on set in that sense,” says the director, whose audacious approach left his two young stars floored.

“Even though you can never really know, we knew what we were making,” says Stone, which Gosling describes as a musical that dares to be different.

“You want to give yourself over to a director who is that prepared to risk everything,” he adds.

• La La Land is in cinemas from Thursday, December 22