"For me, it's about bringing this to a whole new generation," Cox, 42, says. "There are so many people that don't know of the movie and the music and her songs and that kind of thing, so this is an opportunity to do that."
Based on the 1992 blockbuster starring Houston and Kevin Costner, the stage musical follows closely to the original screenplay as singer-actress Rachel Marron hires former Secret Service agent Frank Farmer to protect her from an unknown stalker. Their relationship strays from the professional realm when they fall in love.
The production first premiered in London in 2012, but the upcoming national tour will be the first time the musical is performed in the U.S.
Cox, a multi-platinum recording artist, seems to be the perfect actress for the role, as she appeared on the Whitney soundtrack and knew the late icon personally.
"The two of us were label mates," Cox shares, referring to their affiliation with Clive Davis' Arista Records. "We became very good friends. She was a mentor. There was a real sisterhood between the two of us."
It's this relationship that helped Cox get approval from Houston's family for the project.
"I do have a history with some of the family members, and thankfully with my involvement, I do have their blessing," she says.
While Cox needs no help with the vocal element (she sings just like Houston!), makeup is a different story. Cox enlisted the help of makeup artist Jay Manuel of America's Next Top Model fame to help create her looks onstage.
"We want to be able to get looks that definitely make those stand-out moments that are very memorable," says Manuel, who will use his cosmetic line, Jay Manuel Beauty, to give Cox and the rest of the cast their onstage glow. "We wanted something edgy and different."
The score for the musical includes irresistible classics such as "Saving All My Love," "I Have Nothing," "I Wanna Dance With Somebody," "One Moment in Time," "So Emotional," "Queen of the Night," "Run to You," "I'm Your Baby Tonight" and "I Will Always Love You."
Cox tried to nail down her favorite Houston song for ET.
"That is the hardest question ever," Cox says. "I love the beginning of Act Two where she sings 'All the Man That I Need,' because I think that's really at the core of who she is and where she is in this moment. She's in love. She's just a girl in love, and I think that moment really captures that. It's a beautiful moment."
The touring show will open in Houston's home state of New Jersey when it kicks off on Nov. 25 at The Paper Mill Playhouse in Millburn.