By Stephen Robb
Entertainment reporter, BBC News
Beyonce Knowles' new album arrives months ahead of schedule after the R&B star found herself full of musical inspiration following completion of a new movie.
Knowles waved goodbye to the recording studio during filming
Knowles was not due to record and release the follow-up to her massively successful solo debut Dangerously in Love, which earned five Grammys and 11m sales, until next year.
But shortly after finishing filming Dreamgirls earlier this year, she abandoned a holiday to enter the recording studio.
"I couldn't help it. I just had to go in the studio, I had so many ideas in my head," she tells the BBC News website.
"It ended up being 22 songs recorded in two weeks, and I did three songs a day and I was in the zone."
Dreamgirls is based on a 1981 Broadway musical about a 60s and 70s girl group, with Knowles playing one of the members of The Dreamettes, said to be loosely based on The Supremes.
"I tried to really become this character," she says.
"I didn't allow myself any time to go in the studio or make personal appearances because I didn't want to get myself confused with Deena, who was the character I was playing."
I sang with more emotion than on any of my other records
With no outlet for her musical creativity during the six-month shoot she "felt really bottled up", she admits.
The burst of creativity that followed the end of filming was also a response to the frustrations of her character, who "forgot completely who she was and lived her dreams through her husband", says Knowles.
"Everything that she kind of put up with I felt like I put up with for those six months, and I had so much to say."
Knowles took the unusual step of not telling her music label or management that she was recording, to avoid any expectations surrounding the unscheduled sessions.
"It was definitely liberating - I felt really free," she says.
"It didn't feel like I was trying to make an album, I just had fun."
Chart-topping trio Destiny's Child split last year
But she adds: "I'm in a very calm place in my life but if you heard the record you might think that I was not, because it's very aggressive.
"I am saying all the things that I wish my character would have said."
While this means the songs are not directly about her own experiences, the former Destiny's Child star believes they are the most powerful of her career.
"I am speaking for every woman. It's a celebration of a woman being really strong and knowing what she wants, and what she's worth and not putting up with things that she doesn't need to put up with.
"I sang a lot, I belted a lot, I growled a lot - I sang with more emotion than on any of my other records."
In keeping with the album's celebratory feel, a worldwide release date was set to coincide with Knowles' birthday on 4 September, and is appropriately entitled B'Day.
The singer, who will be 25, is due to tour on the back of the album from next April.
In the meantime, Dreamgirls' arrival in cinemas worldwide from December could mark Knowles' emergence as a credible actress.
"It just was everything that you dream of in a character," says Knowles, whose best-known film work has been in the comedies Austin Powers in Goldmember and The Pink Panther.
"I am able to be funny, I am able to be manipulative, and a little evil, and really sincere and sensitive, and there are really dramatic scenes where I am emotional - I get to do all these things and show that I'm an actor.
"I wanted to prove to myself that if I'm given the opportunity and if I spend as much time and am as focused about acting as I am singing then I can do it.
"I would have done it for free," she adds.