It's been a long time since either Ryan Gosling or Emma Stone had to audition for a part but their early failures to impress form the basis for La La Land, Damien Chazelle's musical love story set in Hollywood.
Stone and Gosling are reunited for their third film together to play two lovers, Mia and Sebastian, who have moved to Los Angeles to try to succeed in showbiz.
"Damien asked us to tell him about our audition disasters when we were first trying to make it," recalls Gosling. "I remember going to one and half way through the agent took a call and was talking about her lunch plans all the way through. I was completely traumatised - and I'm still waiting to hear about the role.
"That ended up in the film but Emma gets to go through it this time, not me."
Stone, who moved to Hollywood with her mother when she was 15 years old in order to try to act professionally, remembers "struggling to even get an audition that year and when I did, often being turned down after singing or saying one line".
"It was nothing quite as devastating as what Mia goes through but everyone thinks about packing it in after a terrible audition," she continues.
"Several times I thought about quitting. Even after I started getting parts in films, I would think, 'You know, maybe I won't do another one.'"
Stone has had no bad experiences with La La Land. She was awarded the best actress prize from the Venice Film Festival, while the film, amongst glowing reviews, has been described as "a sun-drenched masterpiece". After also winning over North American critics at the Toronto Film Festival, it's now tipped as a best picture contender for the Oscars.
Chazelle, who was also nominated for an Oscar last year for another music-centred film, Whiplash, says he "always wanted to make a musical, even if they're not seen as fashionable any more".
"In many ways Whiplash was the film I made because I didn't yet have the budget or trust to make La La Land," says Chazelle.
"We all need hope and romance on the screen and I think there's something about musicals - movies are a dreamland, and a world where you break into song when your emotions are strong, that violates the rules of reality. Isn't that what movies should be about?"
Stone had just starred on Broadway when she was picked for the role but Chazelle says the couple's overall lack of experience in musical theatre harks back to the Golden Age of Hollywood where stars like Audrey Hepburn weren't initially seen as naturals for musical roles.
"I wanted to make characters you could be sitting in a bar with, not people who come to the screen waiting for their moment to shine," says Chazelle.
"My whole idea was to take the old-fashioned magic of the musical, make it about today where real life can't live up to the dream, and ground every moment of it with actors who were invested in giving it realism. That's actually why it works as a fantasy."
Both actors had to learn ballroom dancing and Gosling went one step further to learn the piano to play the aspiring jazz musician Sebastian.
"I didn't learn to read music," he says. "I learned all the songs by heart from a tutor. So we didn't need a piano double in the end. Every frame you see of hands on the piano, it's me.
"I still play but I can still only play the songs from the movie."
Gosling and Stone last worked together in 2011 for the romantic comedy Crazy, Stupid Love, with a chemistry Gosling says, "We don't have to work at. We don't have to create a relationship.
"Hopefully the fact that we're not necessarily natural choices for a musical means we can make it accessible to those who don't necessarily go and see the genre.
"I knew the music was beautiful in La La Land and I thought, 'If we get it right, this will be great.'"
Stone calls the film "the antidote to cynicism, which is so prevalent today".
"It comes down to the hopefulness and the joy of the story. It's not that there aren't cynical or bittersweet moments, but the film itself isn't. It's full of dreams and hope."
La La Land is showing as part of the London Film Festival, running from 5-16 October 2016.
The film will be released in UK cinemas in January 2017.