She's sold millions of records as part of pop group Danity Kane, and she's toured the world, playing for screaming fans. Now, Aubrey O'Day is getting ready to trade in her hair extensions for some "Hairspray."

On Friday, the sultry songstress will make her Broadway debut in the stage adaptation of John Waters' 1988 film classic. And when she takes the stage for the first time, she'll have plenty of supporters in the audience, including the rest of her DK bandmates and the man who discovered them all: Sean "Diddy" Combs.

O'Day, who became an official member of the cast about two weeks ago, says acting has always been a passion of hers. Before pursuing a music career, she was more involved in theater, so this stint on the Great White Way is something of a dream come true.

"I originally started out in musical theater when I was 4 -- I did 'Annie,' " she said. "I've been doing it for a very long time, and this is my first love. My dream in life was to be on Broadway, so this is actually allowing me to fulfill my dreams."

O'Day will be portraying Amber Von Tussle in the production, [article id="1534130"]a role previously played by Haylie Duff,[/article] Hilary's sister.

"Amber is known to everyone as the snot of the cast," O'Day said. "She's the little brat, but one thing I noticed when I saw other people play her is that she's still lovable. She's not someone you want to hate.

"This show focuses on a lot of racial issues," she continued. "It's important, I think, especially with Obama coming out and the turn our country is going through, racially. It's really the only thing on Broadway addressing that. In general, we shy away from race. This show directly puts it out there. It's very powerful. The first time I saw it, I cried -- I was so emotionally invested in it. I think that Amber represents someone who is comfortable with how things are and doesn't want things to change. I mean, sometimes ignorance is bliss, and she just doesn't know any better."

O'Day, who recently broke one of her middle fingers after slamming it into a wall during a DK live gig, jumped at the opportunity to play Amber because she's always loved Waters' version of "Hairspray" as well as the 2007 remake, which starred John Travolta and Zac Efron, among others.

"I've always been a big fan of the 'Hairspray' movies, but they're very different from the show," she explained. "The show captures different elements, so even though I was a fan of those coming here, I had to learn a completely different style of what I perceived it to be."

She also had to tone down her DK persona, given that the musical is set in the 1960s. "We are so contemporary -- [we have] these sexy moves and we are these powerful girl stars," she said. "Then you come here, and sexy is when you were really cute and sweet, and everything is very old-fashioned, and kissing a boy is huge. It's a different time in society, and it was a different mentality back then."

Of course, [article id="1590198"]O'Day's bread and butter is Danity Kane[/article], so as much as she loves to act, don't expect her to hang up her 5-inch heels anytime soon.

"Danity Kane is my first priority in the entertainment industry right now -- it's what I came in doing, and I have so much respect for the group and for our label and everything we were able to accomplish," she said. "This came at a time when I had time in our schedule to do it, and it's amazing that I can do both. It takes a lot of work, and I don't sleep a lot. I definitely kind of have to suck up the hard days and just keep moving."

O'Day is also preparing the release of her clothing line, Heart on My Sleeve.

"It's an online store, HeartOnMySleeveShop.com, and all of the products are T-shirts [that] talk about love and relationship heartbreak -- everything from the good and the bad and the ugly," she said. "Most of it's ugly, because that's what I've experienced at 24, but I'm sure they will get happier as I get older -- hopefully."