By AMY OLIVER
Miserable: Hathaway plays troubled French factory worker Fantine who is forced to cut and sell her hair and become a prostitute in order to survive
We know she can hold a tune thanks to her performance at last year's Oscars.
But it sounds like Anne Hathaway has been putting the practice in for her role in upcoming film Les Misérables.
The Hollywood actress's singing takes centrestage in the first preview of the epic movie due out in December, which also stars Amanda Seyfried, 26, Hugh Jackman, 43, Russell Crowe, 48, and Eddie Redmayne, 30.
Looking gaunt, the 29-year-old belts out classic I Dreamed A Dream against a moody backdrop of 19th century France. Hathaway plays troubled French factory worker Fantine who is forced to sell her hair and become a prostitute in order to survive.
At one stage in the preview, Hathaway is seen weeping as she has her long locks chopped. The actress actually had her hair cut off in the film and is also thought to have gone on a controversial 500-calorie-a-day crash diet where she shed a stone in 20 days.
Long and short of it: Anne's character cries as she has her beautiful locks shorn off
Belter: Hathaway and the rest of the cast sung their songs live rather than lip-synching to a track. Director Tom Hooper called the actress's I Dreamed a Dream 'just jaw-dropping'
Les Misérables, which is directed by King's Speech Oscar winner Tom Hooper, tells the story of ex-prisoner Jean Valjean, (Jackman) who is hunted for decades by the ruthless policeman Javert (Crowe) after he breaks parole.
When Valjean agrees to care for factory worker Fantine’s (Hathaway) young daughter, Cosette (Seyfried), their lives change forever.
Epic: Les Misérables tells the story of ex-prisoner Jean Valjean, played by Hugh Jackman, who is hunted for decades by the ruthless policeman Javert, played by Russell Crowe, after he breaks parole
Easier: Jackman said it was actually easier to sing live rather than having to make it look like you are singing
All the dialogue in the film is sung live by the actors; usually they would lip-sync to a pre-recorded track.
Hooper told USA Today it was the only way he wanted to do it.
He said: 'If you are miming to a playback, even if the synchronisation is done very well, there is a part of you that knows something is off, something is false. When it's live, you believe it so much more.
'The actors have complete freedom rather than following a recording done three months before.'
On a mission: Russell Crowe as ruthless policeman Javert
All-star cast: The film also stars handsome My Week With Marilyn actor Eddie Redmayne
Beauty in a bonnet: Amanda Seyfried plays Fantine's young daughter, Cosette
And Hooper had praise for Hathaway's performance. He said: 'Anne has been an extraordinary exponent of singing live.
'Her I Dreamed a Dream is just jaw-dropping. It is so raw and heartfelt. It's done in a way you could never do in playback.'
Jackman said it was actually easier to sing live rather than having to pretend to be singing along to a track.
Beautifully shot: A bird's eye view of Fantine's factory appears in the trailer
Legacy: The film has been adapted from the smash hit stage show that has been seen by more than 60 million people in 42 countries and in 21 languages around the world
Sacha Baron Cohen and Helena Bonham Carter co-star in the movie, while I'd Do Anything finalist Samantha Barks plays the role of Eponine.
The film has been adapted from the smash stage show that has been seen by more than 60 million people in 42 countries and in 21 languages around the world.
As well as I Dreamed A Dream, other songs include Bring Him Home, One Day More and On My Own.
The film has been adapted from the smash stage show that has been seen by more than 60 million people