NEW YORK — For someone about to make her stage debut, Ashanti appears eerily relaxed.

The Grammy-winning singer and actress exudes a sense of calm during a lunch break from vigorous rehearsals for the New York City Center revival of “The Wiz.” Not a drop of sweat—nor hint of nerves — can be detected as the fresh-faced, bubbly 28- year-old gabs excitedly about playing Dorothy in the rock-soul version of the classic L. Frank Baum tale.

But don’t be fooled: She’s working hard to fill those famed ruby red slippers. Her skills as singer, actor and dancer are being put to the test as the clock winds ever closer to Friday’s first preview performance. The show officially opens tonight for a run through July 5.

“It’s a lot,” says Ashanti, sporting a yellow T-shirt, jeans, sneakers and large gold hoop earrings. “It really is. When we first took the project on [in early May], I said, ‘Wait a minute. Is this the real start date?’ ... I thought it was a lot to learn in such a little time and, when you first look at the script, it’s very very overwhelming.”

Ashanti knows a thing or two about Dorothy Gale: She portrayed the character in 2005 in the TV movie “The Muppets’ Wizard of Oz.” Still, she was initially nervous about how the seasoned cast of “The Wiz” would accept her as a nonstage actress and newcomer. (Ashanti has two multiplatinum albums under her belt, and has appeared in the movies “Coach Carter” and “John Tucker Must Die”).

“It’s a little cliquey,” she says. “Broadway has, you know, the Broadway crowd! ... So coming into it, you’re like, ‘OK, I hope everyone is cool and down to earth,’ so I was very happy and excited to learn that everybody’s all cool.”

Ashanti’s cast mates include Orlando Jones as The Wiz and LaChanze as Glinda the Good Witch. LaChanze, a Tony winner for “The Color Purple,” encouraged Ashanti to experiment with the role and try new things.

“Everyone is gelling really well, we’re laughing and joking and it just feels really good,” Ashanti says. “Because it’s like teamwork: Everyone wants everyone to do well, and they’re fully supportive. Any questions that I have they’re like, ‘I got you!’”

According to director Thomas Kail, Ashanti has been fully committed.

“That sense of calm is partly because she’s prepared,” Kail says. “And she’s prepared to do things in one way and then can stop on a dime, and do them the other way — and is very open to taking direction and to considering new ideas and new objectives within a moment.”

The acting process comes easily — as a repeat Dorothy, she’s been down that Yellow Brick Road before — and she draws upon her personal journey from young pop sensation to blossoming adult.

Ashanti, whose most successful album was her 2002 namesake debut, which had the R&B hit “Foolish,” says she was a little naive starting out in the entertainment business but gradually learned to “stay away from the monkeys and away from the witches.”

But in “The Wiz,” it’s not wicked witch Evillene that gives her trouble. It’s memorizing the music.

“When I’m singing someone else’s [songs], I got to remember — you know — the lyrics!” says Ashanti.