Chris O'Dowd has revealed his "fake it 'till you make it" attitude to singing, as he promotes new movie The Sapphires at the London Film Festival.

In the film, the 33-year-old plays a 60s music man who forms an Aboriginal girl group who play for American troops fighting in the Vietnam War. It is based on a successful 2005 play of the same name.

Speaking about singing, Chris said: "I feel like my soul music singing is fake it 'till you make it. It doesn't matter if it's not all quite in key, as long as it comes from the heart."

He also revealed how he learnt to play the piano for his role in the film.

"That was hard because I was shooting something else while we were doing pre-production. I was learning how to play a piano on an iPad app on airplanes, which doesn't really have the feel of a big music venue but what are you going to do?"

The Sapphires is released in the UK on November 7.