Anne Hathaway nervous performing in front of will.i.am

Anne Hathaway was "intimidated" about singing in front of will.i.am.

The actress loved working on new animated movie 'Rio' - in which she voices the character of outspoken macaw Jewel - and though she was happy to do whatever was asked of her by director Carlos Saldanha, she couldn't help but worry about showcasing her vocal skills in front of the Black Eyed Peas star, who also has a role in the film.

She said: "Carlos can get me to do anything. Every time I would come in, he would show me more footage, and it was just breathtaking. It really was. So, when he said, 'Can you sing?,' I couldn't say anything, but yes. But, it is intimidating to sing in front of Sergio Mendes and will.i.am, as I'm sure you can imagine.

"That morning, I had an extra cup of coffee to steel my nerves."

Despite her fears, Anne enjoyed the experience and wouldn't rule out doing more singing in future.

She added to Collider.com: "Singing has always been something that I've loved to do, but I never thought about doing, professionally. I always felt more drawn to acting. But, who knows? I'm doing things that I never, ever thought I would do, in front of a lot of people, so anything is possible."

Anne is expected to use her vocal abilities in a forthcoming biopic about Judy Garland, but is worried fans of the 'Wizard of Oz' star will scream "murder".

She said: "I certainly don't sing like Judy Garland but the talk is to have me do the singing. But I think people might cry murder if they don't get to hear Judy's beloved voice so the talk is for me to sing but I don't know if that's exactly what will happen."