Keira Knightley needed to make a ''positive'' movie after filming 'Anna Karenina'.
The British actress plays the lead character in the Joe Wright-directed drama - an adaptation of Leo Tolstoy's classic novel - and she admits following on from that she wanted to do something more upbeat, causing her to sign up to the role of Greta in 'Can A Song Save Your Life?'.
She said: ''I can safely say that I am not a singer, and I am not a dancer, but I gave it my best shot in both. It was great. 'Anna Karenina' was such an intense, wonderful experience but it was pretty dark, but the depths that Anna goes to, it was quite tiring.
''I really fancied this year doing something incredibly positive, so I went away to New York and made a film that was incredibly positive, so that was nice!''
However, she was not scared to get to grips with the Russian character in 'Anna Karenina' and was keen the new version of the classic Tolstoy tome didn't make her too simple.
She added: ''We didn't want to simplify her or make her too easy - I don't think that's the point of her, she's this incredibly complicated, strange, jewel-like creature, so we wanted to bring as much of that out as possible. So yeah I did do a lot of work on the book.''