If there’s one song that pervades the holiday season each year, it’s Mariah Carey’s “All I Want for Christmas Is You.” It’s played so incessantly from every department store and radio station during the month of December that we can’t seem to shake the shrieking soprano notes from our brains until the calendar flips to the next year. But the best way to dispose of a tired meme is to beat it to death, and so Jimmy Fallon and Mariah Carey decided to double-down on the holiday tune — by playing it with toy instruments. Taking a cue from what Fallon’s show did with Carly Rae Jepsen and her equally infectious “Call Me Maybe,” Fallon, Carey and The Roots recreated the song with plastic xylophones, a small children’s choir and the requisite tacky Christmas sweaters. It’s catchy (and classic) enough to make us forget how crazy the song makes us.