We are forever grateful for Mariah Carey, The Roots, and Jimmy Fallon singing "All I Want For Christmas Is You."

UMMM, do we know whose brilliant idea it was to have Mariah Carey, Jimmy Fallon, and The Roots perform Mariah's classic "All I Want For Christmas Is You" using only CHILDREN'S INSTRUMENTS? We'd like to send them a bouquet of flowers and maybe find some way to rig the lottery so they'd win every time, because this video is the gift that just KEEPS ON GIVING! And here we thought Mariah's festive cleavage would be the highlight of the season, but NOPE! It's definitely this video of, once more for emphasis, The Roots, Jimmy Fallon, and Mariah Carey singing "All I Want For Christmas Is You" -- with children's instruments. One of which is very similar to this stunning plastic mini xylophone. WE'LL NEVER BE OVER IT.

Watch Mariah Carey, Jimmy Fallon, and The Roots Sing "All I Want For Christmas Is You" after the jump.

Mariah Carey appeared on "Late Night With Jimmy Fallon" starring in what we now will call "our favorite Christmas movie ever." In similar fashion to Christina Aguilera's slaying of "Your Body" with office supplies, the clip begins with the "Late Night" crew singing the familiar opening line of Mariah's tune. Next thing we know, Mariah, queen diva, saunters in (rocking a floor-length red gown, no less), and belts out her holiday classic. While all of this goes down, Jimmy and The Roots accompany Mariah with classroom instruments you might find in a kindergarten music appreciation class. And did we mention there's an actual children's choir that pops up occasionally to add vocals to the chorus? And while all of this is happening, Mariah still werques her diva hand/"I'm singing an important note" move? Again, WE'RE STILL NOT OVER THIS, and we don't anticipate that we will be for a VERY long time.

+ Watch Mariah Carey, Jimmy Fallon, and The Roots Sing "All I Want For Christmas Is You."

Photo credit: NBC