Susan Boyle's duet with Elvis Presley is being released as a Christmas single to raise money for charity.
Royalties from the version of O Come, All Ye Faithful will go to Save The Children.
The singing star, who shot to fame on Britain's Got Talent, said: "Duetting with Elvis was beyond my wildest dreams. And now that this is able to raise money and help children is simply fantastic."
Susan, who has become an ambassador for the charity, filmed the video for the track at a Glasgow primary school.
She said: "I've had the privilege of spending time with families from a Fast programme - Families And Schools Together - that is run at a school in Glasgow. To see the money raised in action and the difference it makes to these families is wonderful. It really does help people.
"The children from the Fast programme also joined me for the music video. We had a lovely two days and the children were fabulous. They were all stars."
The single, from the star's fifth album, will be released on Sunday December 8.
In a recorded message to a central London press conference, music supremo Simon Cowell said he was "proud" of the star.
He said: "No-one of all the people I've met has a bigger heart than you."
The charity's chief executive, Justin Forsyth, said he hoped the song would "highlight the plight of children around the world".