Scheming friends from a council estate - 'everything' James McAvoy wanted

California Schemin' tells the true story of two Scottish musicians, rejected by the music industry, who reinvented themselves as American rappers Silibil N' Brains.

Gavin Bain and Billy Boyd from Dundee were so convincing they won a record deal, appeared on MTV, and supported Eminem on tour before their ruse was uncovered.

For James McAvoy, who grew up in the Drumchapel area of Glasgow it was the obvious story to tell in his first film as director.

"I was keen to do something entertaining, but I was also keen to do something about people from a background like my own - lower income, lower socio-economic level on the ladder and not a lot of opportunities," he says.

"Those kinds of people don't generally get aspirational entertaining movies made about them so when a film came along to me that gave me a chance to tell a story about people from council estates, which was good fun but still underpinned by real stakes and real loss as well, it was the perfect opportunity to do everything I wanted to do."

The film is based on Gavin Bain's memoir, which was made into a documentary The Great Hip Hop Hoax in 2013.

Although both had explored the story of the Dundee duo being rejected at a London audition by record company executives who mocked their accents, and how they convinced the same industry they were rappers from California, McAvoy was keen to explore their friendship as much as the swindle.

"It felt weirdly quite personal to me, even though I've never been into hip-hop music," he says.

"I feel that they're people that I recognise from growing up."

The script – by Elaine Gracie and Archie Thomson – focuses on the relationship between Gavin (played by Séamus Ross McLean) and Billy (played by Samuel Bottomley) who have to reject their Scottish identity in order to pursue their dream.

McAvoy added: "It's such a rude awakening for them when they're told because you're Scottish, you can only go this far, you can only play pubs in your own home town."

"And that's devastating. You need to sacrifice your authenticity, your identity, your integrity."

In one scene-stealing cameo from James Corden as an M&M-munching record executive, they're asked where they come from.

Beverley Hills, they say. The estate, they add. The projects, they correct - too late.

"These are cornerstones of hip-hop," says McAvoy. "That authenticity and that sense of place in the streets that made you.

"That is the lifeblood of rap music and hip-hop music, and they had to sacrifice that.

"But you have to accept that comes at a price."

McAvoy, who has appeared in 30 films including Filth, Atonement, and X-Men, set the bar high for his cast – who had to act, rap, skateboard and perform at a specially arranged gig at Glasgow's Barrowland for 2,000 extras.

"I needed them to be able to skateboard, beatbox, freestyle," McAvoy said. "But I needed them to have chemistry.

"The film's not about two individuals, it's about a friendship."

Alongside Séamus – who is the son of Ricky Ross and Lorraine McIntosh of Deacon Blue – and Sam, is Lucy Halliday - who plays Billy's girlfriend Mary.

Like McAvoy, she first discovered acting at PACE youth theatre in Paisley.

As for the real Silibil and Brains, they've both seen the film.

"Gavin was in tears, I'm told, which I think, is a good sign," McAvoy said.

"Billy told me it was a rollercoaster watching it, because even though we've taken liberties with some of the story, it's by and large what they went through.

"He and Mary watched it with their three kids, and I think it was an absolutely wild ride, but very emotional for them as well."

And is "a wild ride" how he would describe his debut as a director?

"I'm really proud of it," McAvoy admitted. "It's definitely the film I wanted to make but it was mega stressful and a real eye-opener into what all these directors that I've worked with for 30 years must be going through, trying to get me to do exactly what they want me to do. They go, 'Action!' and then I don't do it.

"I thought I'd be some sort of actor whisperer with 30 years of acting behind me.

"But I learned that doesn't necessarily translate into me being brilliant at talking to actors."

With all that stress behind him, McAvoy is ready to do it again.

He said: "When I first said I wanted to direct, I got half a dozen gritty Scottish dramas about unemployment, and now I've made this, I'll probably get half a dozen music bio-pics, but I don't know if that's what I want to do.

"I'm interested in relationships and the stuff that happens between people,.

"I realise that's pretty vague but I'm sure there's stories out there that I'll be able to tell."

California Schemin' closed the Glasgow Film Festival and will be in cinemas from 10 April.