The star of a new West End musical based on the film The Bodyguard says she does not want to be compared to the late Whitney Houston.
Heather Headley and Lloyd Owen are to take on the lead roles made famous by Houston and Kevin Costner in the 1992 movie.
"It's going to be the greatest challenge of my life, but I'm ready to step into those heels," said Headley.
The new musical is due to open at London's Adelphi Theatre in December.
It will feature many of Houston's greatest hits, including Saving All My Love, How Will I Know, I Wanna Dance With Somebody and I Will Always Love You.
Houston, one of the world's best known singers in the '80s and '90s, was found dead in a Los Angeles hotel room on the eve of the Grammy Awards in February.
Trinidad-born Headley said her preparation for the role in the musical was like "training for a tough marathon".
One of the challenges, she said, was separating the character of Rachel Marron from Whitney Houston.
"You don't want people to compare you to Whitney. I didn't want it before and especially not now after her passing.
"I want people to come in and say this is Heather's version - this is Heather playing Rachel Marron and singing Whitney songs.
"I am always trying to find a way to make them my own but still acknowledge and keep the integrity of her music."
Headley, who will be making her West End debut, originated the role of Nala in The Lion King on Broadway. She went on to play the title role in Aida, for which she won the Tony Award.
Her third studio album, Audience of One, won a Grammy award for best contemporary R&B gospel abum in 2010.
'Biggest Whitney fan'
The Bodyguard's producers, Michael Harrison and David Ian, began work on the musical six years ago.
They managed to enlist respected theatre director Thea Sharrock for the project because she was "the world's biggest Whitney fan".
Sharrock is better known for her work at the National Theatre. Her production of After the Dance won the 2011 Olivier award for best revival.
She is currently directing Danny DeVito and Richard Griffiths in Neil Simon's The Sunshine Boys at the Savoy Theatre.
Sharrock admitted at Tuesday's launch event at the Savoy Hotel that she had once played I Wanna Dance With Somebody to inspire two actresses who had been struggling with a scene.
"The two girls went crazy, it was like a school disco. They did the scene and they did it brilliantly. I don't know why that worked, but it did."
She added: "Later they came up and said, 'If there is a Whitney musical you have to have to direct it.' I said, 'That is a deal', and here I am."
The Bodyguard tells of Frank Farmer, a former secret service agent turned bodyguard who is hired to protect superstar Rachel Marron from an unknown stalker.
Lloyd Owen, who plays Farmer, has had a long stage career and is best known for playing Paul Bowman-MacDonald in BBC drama Monarch of the Glen.
The Bodyguard will be his first musical, but he hinted that he would not have a conventional singing role.
"If you think of Frank Farmer singing and tap-dancing, he loses his enigma and it could potentially be quite cheesy. That's not the case in this," he said.
The Bodyguard begins previews on 6 November and will have its opening night on 6 December.