Sarah McCarthy talks about The Sound of Mumbai: A Musical, which one Toronto programmer predicts will be a sleeper hit of the festival.

Someone who could turn out to be of the most captivating stars at Toronto 2010 won’t be walking the red carpet. Ashish, the 11-year-old star of Sarah McCarthy’s documentary The Sound of Mumbai: A Musical won’t be attending the festival because he’s busy with schoolwork back home.

But he makes a big impression on screen. McCarthy’s third documentary follows Ashish and his classmates who are living in Mumbai’s slums but invited to perform a lavish Sound of Music concert with the Bombay Chamber Orchestra at Mumbai’s famed National Centre for the Performing Arts.

The genesis of the story came from McCarthy’s friend. “My mate Joe Walters directs the Orchestra and he had always told me that they would make a good film, but I thought it was a bit boring. So when he told me about this event where they would be collaborating with kids from the slums, I knew that was a way of getting into the story,” the London-based McCarthy reveals. (Walters produced the project and his opera singer wife also helped finance it.)

When she went for a recce, she was immediately struck by Ashish’s larger-than-life charisma, which also led to the choir director casting him for a solo part despite him not having the best singing voice. “You just can’t help but to engage with him, he stood out to the conductor and he stood out to us as well,” she says.

What motivated McCarthy to spend the time (nine weeks shooting in Mumbai) and money on the project was the kids. “What motivates me is the thought of little Ashish who is so brilliant and dedicated and hardworking and talented. His parents have lost that hope and that joy and that optimism, it would be hard not to. But the idea of that moment when Ashish thinks he’ll probably never be a doctor or a scientist, it just kills me.”

Her passion for the film is amplified by being accepted into Toronto. She says she was shocked when she first got the call from TIFF programmer Thom Powers.”That was the most shocking thing to me, I thought it was some closed club that you had to know someone who knows someone, and I didn’t have that at all. And luckily Thom Powers took a shine to it.”

Indeed he did. Powers has even singled it out as his tip for “sleeper” of the programme. And McCarthy has attracted the attention of Morgan Spurlock, who will be chronicling her journey in TIFF (along with other directors) for a documentary about filmmakers at the festival.

McCarthy studied film in her native Australia before moving to London to work for the BBC and RDF Media. Her TV documentaries include Murderers on the Dancefloor and Black Widow Granny. 

McCarthy says her documentary heroes include Errol Morris and Werner Herzog. “I haven’t had that much formal training, I do it all quite instinctively I think,” she says. Working with children (speaking English as a second language) was another challenge. “Generally what I tend to do is try not to be listening, to try to get as natural a scene as possible…. When you were listening, they would change the way that they’d speak, it suddenly became unnatural. But if you ignored them, it seemed to work.”

The film doesn’t gloss over the whole situation these children face, McCarthy notes. “When I started to realise the one-off nature of the event, that’s when I started to think about what’s going to happen to them afterwards? You get into this incredibly glamorous world that they might never be a part of again. And then it was exactly what I expected the day after, Ashish was gutted.” (She is working with the Akanksha charity to support the kids after the filmmaking process.)

Music clearances have been made for a Dutch TV broadcast (Channel 4’s True Stories strand will broadcast in the UK) and there is progression on licensing for theatrical. (Goldcrest Films is handling international sales.) She hopes theatrical deals will be in play. “Seeing it on the big screen, you can see so much more detail and more expressions on the kids’ faces. It has got such big brassy emotions in it, I think that’s the perfect setting.”

Up next, McCarthy is working on The Dark Matter of Love, which is being financed now. It’s the story of a five-year-old Russian orphan learning to love his new family, combined with background on the medical and psychological approaches to love. “I’m really fascinated by the science of love. It seems like this intuitive emotional thing that we’re born knowing how to do, but that’s not the case,” she says.

In a different vein, she also aspires to work with talent executives to create a Western-looking, Mandarin-speaking girl group in China, to follow their story for a film.