If you love amazing sing-alongs, Mariah Carey and Jimmy Fallon just may have organized one that takes the cake. Joined by the Roots and the cutest kids you've ever seen, the ensemble performed a rendition of Carey's holiday classic, 'All I Want for Christmas Is You.'

The festive jam session took place backstage before last night's episode of 'Late Night With Jimmy Fallon,' showing Fallon in a candy-cane striped sweater and Carey in a red floor-length dress. The diva took the opportunity to insert a few ad libs, but stayed true to the celebrated track.

The Roots also showed up in shades of red, playing various real and toy instruments. The addition of four smiling kids, who popped in and out of the frame like little Muppets, really made the song special, though, not to mention oh-so-adorable.

'All I Want for Christmas Is You' was released in 1994 as the lead single from Carey's fourth studio album, 'Merry Christmas.' The pop star re-recorded the song in 2010 for her second holiday album, 'Merry Christmas II You,' and called the song 'All I Want for Christmas Is You (Extra Festive).' The uptempo tune is widely regarded as one of the best modern Christmas songs.