Well this is a nice Christmas surprise form James Corden and the crew over at his Late Late Show!
He was joined by mega stars this year in his SUV including Selena Gomez, Lady Gaga, Elton John, Demi Lovato, Adele and the Red Hot Chillies.
What we didn't know is that as well as recording all of their hits, they all belted out a version of Mariah's Christmas classic. Brilliant.
The exec producer Ben Winston said:
Very few things that you can say you have worked on for a whole year. This one we can. https://t.co/VzqNCFbkqC
— Ben Winston (@benwinston) December 16, 2016
