Vanessa Williams opens up about starring in new 'The Devil Wears Prada' musical

Vanessa Williams is stepping into the stilettos of the fashion diva Miranda Priestly in a new upcoming production of the musical " The Devil Wears Prada. "

The new role, based on the 2006 movie starring Meryl Streep, Anne Hathaway and Emily Blunt , is one of the biggest in Williams' expansive career so far and one she told ABC News she has been waiting for.

"I channel Miranda through the dialog [from the movie]," the actress and singer told 20/20 co-anchor Deborah Roberts. "A lot of the dialog is actually taken from the actual film. So what you'll hear me do on stage is the dialog that people know and love and have memorized."

That dialog also includes the iconic "That's all" phrase Miranda frequently uses in the film.

"The first number that I do is called 'The House of Miranda.' And the very last words that I sing is 'That's all,' and I walk off," Williams explained. "So ... my first lines are, 'Emily, Emily,' and the audience will know, 'Oh, my God, she's coming.'"

The new "The Devil Wears Prada" musical is set to run in Plymouth, England, and then move to London's West End in the fall and will bring the film's fashion and flare to the stage.

"'Devil Wears Prada' is a perfect movie and that's why it has legs and stands the test of time. This is yet another step to take something that is perfect and bring it into another genre and make it spectacular," Williams said.

Fans of the film will recognize the many lyrics Williams will perform, she added.

"You've got lines that people know -- 'Tell Simone I don't approve the girl she sent me' -- so, you've taken something that people know that she's going to be giving orders and taking and adding music to it and having everybody saying, 'This is the house of Miranda,'" Williams said. "It's layers. It's going to make it bigger and better."

For the new production, Williams also got to work with the legendary songwriter, pianist and performer Elton John and called it an "incredible" experience.

"I grew up with Elton John, like we all did. So, as the pop star, as the icon, and then just to have him write new music and have him listen to my voice and what I'm doing with it and be inspired, like, 'I've got something that we can do. Let's do this.' So it's wonderful to make him smile and to make him feel good and happy," Williams said.

Williams also promised audience members and fans will have a devilishly good time.

"I guarantee you there will be coats being thrown and bags being placed on the desks," she continued. "You're going to see fashion, and you're going to see it worn beautifully and executed amazingly, and the runway sequences are going to be incredible."

At 61, Williams said she is excited to embrace a new role, especially that of a villain.

"When you play the villain, when you play somebody so over the top, it's quite freeing," she said. "And it allows you to kind of sit in your fierceness that you don't often have the opportunity to do."

And along with her new stage role, Williams is also adding adding producer to her resume with new projects.

"I've decided not to wait for things to happen," she said of taking on the challenge. "It's that empowering nature that you're not apologizing for anything and you're not waiting for somebody to make it happen for you. And I think I've just leaned into that whole idea."

After "The Devil Wears Prada" wraps its run in the United Kingdom, the hope is to bring the musical to Broadway, hopefully in the next year.