The chord that makes Christmas music sound so Christmassy

Hint: Mariah Carey’s “All I Want for Christmas is You“ uses it. If you walk around a shopping mall, turn on the radio, or go to a coffee shop between Thanksgiving and Christmas, you’re going to hear Mariah Carey’s “All I Want for Christmas Is You.” It’s one of the only Christmas songs written in the last 20 or so years that has reached the same popularity as the American Christmas standards that came before it. Besides those recognizable sleigh bells, what makes Mariah Carey’s song sound like a classic? Adam Ragusea, a journalism professor at Mercer University, believes it’s all in the chords. He wrote for Slate: I count at least 13 distinct chords at work in “All I Want for Christmas Is You,” resulting in a sumptuously chromatic melody. The song also includes what I consider the most Christmassy chord of all—a minor subdominant, or “iv,” chord with an added 6, under the words “underneath the Christmas tree,” among other places. (You might also analyze it as a half-diminished “ii” 7th chord, but either in