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British pop singer Rita Ora had a steep learning curve for her first major acting role in the highly anticipated " Fifty Shades of Grey."

After eight call backs, Ora finally landed the part playing Christian Grey's adopted sister, Mia, opposite Jamie Dornan.

"I was a bit kind of stressed out during the audition process," she told Access Hollywood recently. "When I got that phone call I was so happy. I couldn't wait to tell everybody."

But the audition wasn't the hardest part: Perfecting an American accent was.

Ora called it "incredibly difficult."

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"I had to have someone in my ear on set telling me what to say before I said it. Because I was honestly so nervous, I forgot everything I learned."

But Ora, who previously had a small part in "Fast and Furious 6," relied on now-good friend Dakota Johnson, who will play Anastasia Steele in the film.

"She really eased me," Ora said. "She was really nice to take care of me."

The "I Will Never Let You Down" singer said fans should be pleased with the film.

"The movie is as close as it can visually be," said Ora, who has read all three E.L. James novels. "I think the actors are phenomenal in this. I'm just honored to be on the same kind of wavelength as them."