Oprah Winfrey is a media icon and one of the most influential women in the world.

But when it came to a return to acting in "The Butler" after 15 years away from the big screen, Winfrey told ABC News she was very nervous.

"It's like having an instrument," she said during a sitdown Monday in New York City for her new movie. "You play the piano pretty well or you play a flute, you play the trombone, then all of a sudden you put it in a corner, cause you go, 'I'm not going to do that anymore, I can't, I don't have time to do that,' which is what I did, that's your acting instrument."

That is, until "The Butler" director Lee Daniels called and asked the media mogul to pick it back up.

"You're like "Uhhhhh!" Winfrey said.

There was one problem. Winfrey had trouble crying on cue. Daniels had a solution. He had her call an acting coach Susan Batson, who had an immediate affect.

"I never met the woman," Winfrey said. "In 20 minutes, she's in my house and I am balling on the sofa and I was thinking, "Oh my God, what is this?"

Batson told Winfrey she was back.

Back enough to stand toe-to-toe with Oscar-winner Forest Whitaker, playing his wife and in one scene, his disco dance partner.

"That's my '70s move," she said of her movie dancing, while greeting Whitaker's character on his birthday, wearing a black and white disco jumpsuit. "I never was a party disco person, but that's my era and I did used to watch 'Soul Train' every Saturday, so I know those moves from 'Soul Train.'"

Whitaker told ABC News that Daniels was off the screen pushing Winfrey to dance faster and faster.

"She really went for it," Whitaker said.

In fact, Winfrey said she "danced for six hours straight all night" to get the scene just right.

Whitaker gushed about Oprah's performance and how the two had wanted to work together for years.

"We had a relationship before because when I did 'The Last King of Scotland,' before any awards stuff, early in the beginning, she invited me to her home and threw a small gathering for me," he said.

In between takes for "The Butler," Whitaker said Winfrey wanted to grow their friendship, so that it would translate to a closeness on-screen.

"We would walk around and sit we each other," he added. "She's so great in this."

(Photo Credit: Jackson Lee/Getty Images)