Having written scores for only three feature films - all directed by longtime friend Michel Hazanavicius - he was largely unknown even in his own country.

But when Hazanavicius' The Artist became an unlikely worldwide hit in 2011, Bource found himself collecting award after award, including an Oscar, Golden Globe, BAFTA, Cesar and European Film Award.

Like all the key contributors to the charming comic romance between a fading Hollywood silent film star and a rising actress from the talkies, including stars Jean Dujardin and Berenice Bejo, he went on a remarkable ride from the moment it premiered to acclaim at the Cannes Film Festival.

Bource admits he had no idea the $US15 million film would even be successful, let alone win five Oscars including best picture and director.

"No, no," he says firmly in the bar of a Paris hotel, translator by his side to help with his limited English. "Not at all."

Bource remembers the moment Hazanavicius mentioned his plan to make The Artist while on holidays on an island off Barcelona.

"Michel announced during the vacation with friends that he had this idea to make a black-and-white silent film," he says. "All the friends laughed.

"But deep down inside, I thought 'wow, this is great. We're going to be able to experiment'. I saw the idea, with all the humility I can imply, to do something maybe like Tim Burton with Danny Elfman."

Bource, who came to composing through short films and commercials, heads to the Sydney Festival next month to perform The Artist Live in Concert. He will play piano and celesta - a cross between piano and glockenspiel - with the Sydney Symphony Orchestra at the Opera House.

"It's unimaginable," he says of the prospect. "It's going to be my first time in Australia. Of course, I've heard of this magnificent orchestra. It's one of the five best orchestras in the world according to its reputation. So we'll see: maybe it's the first."

Bource says that working on The Artist was difficult both musically and personally because of the compromises required.

"It's not always your own music - because you share that with the producer and director - [unlike] composers in the past. In the beginning I thought we'd be able to make more experimental-type music. But when the script was written, it was a love story so I had to make music that would fit the story - more old-style music."

While he has toured Europe performing in concerts with screenings, not everything has gone to plan since The Artist's success.

He went on set in Georgia and wrote music for Hazanvicius's next film, the Chechen war drama The Search, starring Annette Bening and Bejo. But he was hurt when the director decided not to use his music.

"I put a lot of hope and devotion into the project," he says. "But there was nothing in return."

The experience seems to have severed the duo's working relationship.

"I don't think we'll work together in the near future," he says. "Now I want to work on my own projects. I don't want to be directed by someone.

"Not that we're not friends any more. We have lunch together. Michel and I have worked together for a long, long time. There's a fusion between the two of us, the audio and the visual work. But it's the end of the story."

Instead of film, Bource has plunged into bold composing projects for orchestras that take inspiration from radically different sources.

He has collaborated with scientists from CERN, the Swiss particle physics laboratory, for a work that would use sounds from the Large Hadron Collider in concert.

And shocked by women and children being killed by chemical weapon attacks in the Syrian civil war, Bource is writing a homage to the victims that he hopes to perform in concert with an orchestra to raise funds for the country's children.

"The work will be called Questions to Allah," he says."It's extremely contemporary music without melody. Very raw. It's going to be a phenomenal piece - very complicated. Maybe it's a piece you can listen to only once."

He grimaces as he describes the spread of the conflict to other parts of the region.

"The events are only going to get worse," he says.

It's a political focus, a passionate concern for children as victims of war, the seems light years from the simple comic charm of The Artist, though he suggests they are linked by an interest in innocence.

Will he speak to the Sydney Symphony Orchestra about performing the work?

"Why not?" he says. "It's important to make something important."

The Artist Live In Concert is at the Sydney Festival on January 23 and 24. Garry Maddox travelled to Paris as a guest of Unifrance.