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Did you enjoy playing someone so unpleasant?

I loved it. I felt like I couldn't be working with better filmmakers. They are the best at what they do. So I felt really calm. First of all I was so relaxed because I'd worked with Oscar before, so I knew him and loved him. And then when we were filming we could do anything, and with the Coens brothers standing there you know you wouldn't mess up because they're always so good. They'll reign you in or push you in the right direction. So I just kind of let loose. It was so freeing and so great after "Gatsby," which had been an amazing experience and I loved it, but it was a totally different film. I was required to wear dresses and look pretty everyday for six months. To switch to a tiny film in New York where I just bumped around wearing a big black wig was exactly what I wanted.

Was it easy to let loose on stage during the singing bits, where you had to share the screen with a superstar like Justin Timberlake?

It was in the end. First of all I walked into the music rehearsals quite nervous just by being the only non musician. But everyone was so warm and lovely and encouraging. Then I switched gears going 'I'm not a singer, no one's expecting me to be,' so it was fine. And then in the end I loved it. I had so much fun. I thought Justin was hilarious as Jim. We played off each other and really enjoyed it in the end.

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How did shooting the musical portions in this film compare to the centerpiece one in "Shame"?

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"Shame" was a lot more, I spent a lot more time working on that. We had rehearsals, Steve composed the arrangement with the composer. It was a lengthy process. The idea was to use one take so the pressure on that was far greater. And the whole scene was about her giving a message to her brother and all of the stuff going on underneath, so it was much more difficult. The Coen brothers were just fun. It was really fun and relaxing (laughs).

CBS Films has been having a lot of fun promoting the film and pushing it into awards season with live concert events. Has it made the junket process more enjoyable for you?

It helps but it's nice going around when people like the film. It's nice when people love the film and talk about it. The concert was amazing. To get to be there and just to watch Patti Smith and co. perform from the side of the stage was such a privilege. To be in it was terrifying but a couple shots of whiskey and I was on my way. It's the same feeling I had in Cannes. To get to stand on the carpet with these people is really wonderful. To get to see people discover Oscar for real is really exciting and I love watching people's reaction to his performance in the film. That's been my favorite experience.