11/09/2013 11:53 BST | Updated 10/11/2013 05:12 GMT

'As Human Beings We Lie All the Time': Chronicling the Great Hip Hop Hoax

When Jeanie Finlay first heard the story of Silibil n' Brains, she didn't believe it. Two guys from north-eastern Scotland who pretended to be American rappers, fooling one of Britain's most successful pop music managers and one of the world's biggest record labels?

"I thought it was too good to be true," recalls the Nottingham-based filmmaker, whose music documentary about Gavin Bain and Billy Boyd's shape-shifting exploits, The Great Hip Hop Hoax, is now playing at several U.K. cinemas and comes out on DVD 23 September. "And then I saw evidence."

Silibil n' Brains were inadvertently born in the early 2000s when Bain and Boyd, hip hop fans who'd started rapping together at university, travelled from Dundee to London to audition for a record label that advertised a search for the next Eminem. Rhyming in their Scottish brogues, they were laughed out the door, derided as "the rapping Proclaimers."

Rather than get mad, they decided to get even, inventing loud-mouthed American alter egos, perfecting Yank accents, and successfully pitching themselves back to the music industry as Silibil (Boyd) and Brains (Bain), hard-partying skater MCs from California who'd somehow landed in Britain. Jonathan Shalit, who managed Charlotte Church and N-Dubz, signed them as clients; Sony gave them a lucrative record deal.

Bain and Boyd kept up the remarkable masquerade for two years - touring, making videos, getting drunk with celebrities at industry parties - until the strain of living the lie and submerging their own identities finally caught up with them, sundering not just their rap career but their friendship.

"Imagine being tied to someone that you now hate, and the lie is the thing that ties you together," Finlay tells MusicFilmWeb. (Click here to read the full interview.) "My cameraman described it as like a weight around your neck, dragging you into the mire, deeper and deeper and deeper. That's how they were."

The flame-haired filmmaker has been working on Hip Hop Hoax on and off since 2008, when Bain went public about the charade. (It was during a break in the project that she made Sound It Out, her internationally acclaimed DIY portrait of the last indie record shop in her home town of Stockton-on-Tees and its community of sweetly obsessed vinyl junkies.)

Told largely by Bain and Boyd themselves, supplemented by voluminous archival footage - Silibil n' Brains were pre-YouTube pioneers of digitally recording their every move - the film progresses from larky and goofy to darkly bleak as it delves into the tricky territory of identity, fame, and the cost to the former of pursuing the latter.

A like thread about the shifting sands of self-hood when life becomes a performance runs through Finlay's next music film. Orion, now in production, is the story of Jimmy "Orion" Ellis, a singer from the American South with a remarkably Elvis-like voice who signed with Sun Records in the late '70s to perform as a masked, he's-not-really-dead King. The filmmaker says the thematic similarity is no coincidence.

"It's something I'm really interested in and runs through all of my work - much stronger than the fact that they're musical stories, I think," Finlay says. "It's all about, how do we present ourselves as human beings, and what are the things we can do and change that make us who we are? Like in Sound It Out, where the records on your shelf contribute to who you are as a person."

When I suggest it's rather a leap from those Teesside music nerds and the self-reinventing Goths in her debut feature Goth Cruise (about exactly what it sounds like) to the personality crises of Orion and Silibil n' Brains, Finlay says it's just a matter of degree.

"In Hip Hop and Orion they're just much more extreme," she says. "As human beings we lie all the time, but what Billy and Gavin did was so extreme, it can kind of hold a mirror to what we all do."

Herself included? Has she ever pretended to be someone she's not get a film made, or achieve some other goal?

"No, I would say actually that I'm painfully honest, painfully open," Finlay says. "I'm a really, really rubbish liar. Like, really, really rubbish.

"I remember getting interviewed for [admission to] art college, and the panel saying - my best friend had been interviewed before, and they said, 'Wow, your best friend, she'd be an amazing poker player. But you? Don't play.'"