In the U.K., the song fared far better, lodging itself near the top of the singles chart, while in Japan, “All I Want For Christmas Is You” was the best-selling foreign single of 1994. These successes foreshadowed the song’s explosion in U.S. popularity: The song perennially tops Billboard’s Holiday 100 chart, which measures sales, airplay, and streaming, and eventually peaked at No. 21 on the regular Billboard Hot 100 in 2013. It’s also a radio staple: During the 2014 holiday season, “All I Want For Christmas Is You” was the most-played song on Adult Top 40 radio stations monitored by Nielsen BDSradio, earning 751 spins more than its closest competitor, Brenda Lee’s “Rockin’ Around The Christmas Tree.” On Mainstream Top 40 stations, the song trailed only Ariana Grande’s “Santa Tell Me” for dominance.

Capturing that traditional, retro holiday sound

Afanasieff—who co-wrote, produced, and performed and programmed the music on the track—never expected the song to become a hit, he told Billboard. “To think of it as a single that’s going to No. 1, that’s going to drive an album… we didn’t have an inkling of that. That’s not what the time was. That’s what made it such a modern phenomenon: Because it’s not like ‘White Christmas’ or ‘Jingle Bells’—the song doesn’t have any of those traditional elements, but it became a huge pop hit.”

Carey’s playful, lively vocal performance certainly had much to do with this success. Her Broadway-caliber emoting and theatricality was a breath of fresh air during a year when serious power ballads dominated the pop charts. But as Afanasieff recalled to Business Insider in 2013, he wasn’t thrilled with her initial approach: “My first reaction was, ‘That sounds like someone doing voice scales… Are you sure that’s what you want?’” The pair—who had collaborated extensively on Music Box and Carey’s 1991 album, Emotions—eventually landed on the same wavelength, however. “She would sing a melody and I would do a chord change,” he said. “It was almost like a game of ping-pong, back and forth, until we had it.”

Yet musically, “All I Want For Christmas Is You” is hard to pin down as being from a specific era, which helps its enduring appeal. The song begins with a sparkling bit of percussion that resembles an antique music box or a whimsical snow globe. As it progresses, other seasonal percussive signifiers emerge: celebratory church-like bells, cheerful sleigh bells, and an underlying rhythmic beat that sounds like the loping pace of a horse or reindeer. These sounds echo religious and secular musical touchstones, without veering blatantly too much in either direction, and give the song an upbeat, joyous tone.

As Carey noted in a 1994 video interview, “All I Want For Christmas Is You” was meant to be “fun,” she says. “It’s very traditional, old-fashioned Christmas. It’s very retro, kind of ’60s.” In other interviews, Afanasieff name-checked Phil Spector, whose A Christmas Gift For You LP is considered classic. It’s an apt influence: A lush bed of keyboards, reminiscent of a small-scale Wall Of Sound, cushions the song’s cheery rhythms, while a soulful vocal chorus adds robust oohs, tension-creating counter-melodies, and festive harmonies. Most notably, however, the song’s jaunty piano chords and melody keep the song merrily bouncing along.

“I started playing some rock ’n’ roll piano and started boogie woogie-ing my left hand,” Afanasieff recalled to Billboard about the song’s genesis. “And that inspired Mariah to come up with the melodic [Sings.] ‘I don’t want a lot for Christmas.’ And then we started singing and playing around with this rock ’n’ roll boogie song, which immediately came out to be the nucleus of what would end up being ‘All I Want For Christmas Is You.’”

An arrangement simple enough to be infectious

While the music sounds busy, its arrangement is actually “very simple,” he said in a 2014 ASCAP interview. “In fact, so simple that, at the time, I thought it was overly simple, and I really didn’t like it. Because music people know [Sings the intro’s stair-step notes.] it’s almost a practice interval.” Still, merging these rudimentary melodies and parts with a familiar-sounding, rock ’n’ roll foundation was a winning formula, especially in terms of crafting a song that sticks: “Keeping that tradition—and then the oversimplified melody—I guess because it was that, made it so easily palatable for the whole world to go, ‘Oh. Yeah, I can’t get that out of my head.’”

Although the song itself is relatively uncomplicated, it’s a mistake to consider “All I Want For Christmas Is You” thematically slight. The song isn’t emotionally attached to common holiday traditions: Stockings hung on the mantel, Santa bringing toys, reindeer, mistletoe, and even snow all pale in comparison to the “you” the song’s main character longs to see. “Going into an original Christmas song, you gotta be really, really smart to know all the landmines you’re going to be stepping on,” Afanasieff said in the ASCAP interview. “If a smart writer writes a song—and just boldly goes into the stereotype of jingle, and mistle[toe], frosty and Rudolph and Santa—ugh, God, it just becomes a mess.” Here these festive signifiers are a mere backdrop for the song’s more universal premise: pining after someone who’s far away, and wishing they were there with you.

“A lot of people can relate to the sentiment of being away from someone you love during the holidays and what a drag it can be,” Dikembe guitarist Ryan Willems, whose band did a slower, downtrodden version of the song in 2013, tells The A.V. Club. “What the original did that was brilliant was it dressed those sentiments up in one of the most palatable and joyful sounding Christmas songs of all time. As far as Christmas music goes, I think this song is more substantial and genuine than most.”

The rare, full-on Christmas love song 

In this way, “All I Want For Christmas Is You” transcends its seasonal association and taps into something far deeper and more pervasive, something people struggle with year-round. While the song certainly can’t be divorced from the holiday—what with the gift-driven double entendre in the title and chorus—it’s not limited by its Christmas setting, either. Afanasieff said in the ASCAP interview, “I think people like this positive love song, because it’s interchangeable. Anybody can sing it to anybody—it’s about everybody… from father to child or mother to child or wife to husband.”

Yet such ambiguity makes “All I Want For Christmas Is You” incredibly mutable. The song can just as easily be interpreted as a melancholic song about unrequited love, especially because it’s all crescendo and no denouement: Listeners never find out if the main character actually gets her wish—much less if the person she’s confessing her love to actually feels the same way. “All I Want For Christmas Is You” is a one-sided confession of wants and desires, not a song describing or celebrating a consummated relationship. “Honestly, the lyrics, to me, come off as hopelessly sad,” Williems says. “I’ve read the critical reception section of the song’s Wikipedia page, and I can’t help but think the critics weren’t really listening. One critic seems to claim there is a ‘hint of longing,’ which might be the understatement of the century.

“If you wanted to get real bummed about it, I think the argument could be made that the song is denouncing the artificiality surrounding the spectacle of Christmas,” he continues. “Saying that you are so hung up on the negative of not being with one person on Christmas that you can’t embrace the joy of the holiday is really pretty sad, but also movingly honest for a pop Christmas song.”

The song inspired a slew of unusual, left-field covers

But the song’s thematic flexibility also makes it ripe for other, less-serious interpretations. Zebrahead bassist Ben Osmundson tells The A.V. Club that the aim of his band’s racing, pop-punk version of the song “was to have a Christmas song that we actually really liked,” he says. “Sometimes cheesy is good. At least to us.” On their 2010 EP, Ruin Christmas, the Oakland indie-garage trio Shannon And The Clams took a shambling, lighthearted approach to their “All I Want For Christmas Is You” cover, including having guitarist-vocalist Cody Blanchard sing lead. “We wanted a male voice singing it because it’s in such a high register and so feminine,” he said in an email to The A.V. Club. “It came out so scream-y and funny. We wanted people to chuckle but also to be reminded that this is simply a good pop song that they all had probably written off as dumb ’90s Top 40.”

Blanchard also found the humor in the song’s lyrics. “It’s got a good punchline thing going with each verse, where she describes in a dozen different ways each of the Christmas wishes she would trade in to spend this Christmas with her bae,” he says. “She’s telling Santa Claus that she doesn’t need any of the usual stuff; she’d rather he just bring her lover to her instead. I think it’s a relatable feeling for a lot of people, torn between friends and family and lovers, or just wishing there were some powerful being who could bring your baby to you when you’re missing him/her.”

My Chemical Romance’s punk- and metal-inflected “All I Want For Christmas Is You,” meanwhile, mines the song’s desperation. In fact, their version sounds unmoored and frantic, perhaps because the cover came about after the band wasn’t able to come home for the holidays during one of their first U.S. tours. “We weren’t depressed, but it was the first kind of wake-up call as to what touring was like,” vocalist Gerard Way said in a 2005 interview with Black Velvet magazine. “We were freezing cold in the van, and the Mariah Carey song came on the radio, and this was back when we used to carry knives and weapons and stuff, ’cause you needed to. And there was something about that song, because it would get me so excited, but it was really violently excited. I just remember swinging a knife around and freaking out because the song made me so goddamn happy. So instead of covering a classic song or instead of writing a new song, we decided to pick this ridiculous song and see what we could make of it.”

Left-field covers like these have helped “All I Want For Christmas Is You” become part of the permanent Christmas canon, because they expose an entirely different audience to the song. Strangely enough, however, there are only a few rock-based versions of the song out there besides the ones mentioned; other notable takes include a nostalgic new wave version by The Motels and an energetic, pop-rock rendition by Bowling For Soup. However, “All I Want For Christmas Is You” is a favorite of mainstream pop stars; Michael Bublé, Ariana Grande, Miley Cyrus, Idina Menzel, Fifth Harmony, Lady Antebellum, and the cast of Glee have all tackled it.

How Mariah Carey keeps All I Want For Christmas alive

And Carey herself always keeps the song in the public eye, via high-profile performances at the Macy’s Thanksgiving Day Parade and the Rockefeller Center Christmas Tree Lighting, as well as the occasional rework. She’s re-done the song with a hip-hop-tinged rhythm track and guest raps (2000’s “So So Def” remix, featuring Jermaine Dupri and Lil’ Bow Wow), electronic beats (2009’s hi-NRG “Mariah’s New Dance Mix”), an orchestral intro (2010’s “Extra Festive” mix), Jimmy Fallon and the Roots (a 2012 version on classroom instruments), and as a duet with Justin Bieber (a 2011 version on his holiday album). Wisely, Carey has also diversified how and where the song is promoted: This year, she released a children’s picture book named after the song.

In 2003, “All I Want For Christmas Is You” also appeared in a pivotal moment near the end of the movie Love, Actually. An American ex-pat named Joanna (Olivia Olson) brings the house down at the school holiday musical with her rendition of the tune, which presages David (Hugh Grant) and Natalie (Martine McCutcheon) accidentally exposing their relationship. This take on the song emphasizes the bravery built into “All I Want For Christmas Is You”: After all, there’s nothing tentative about bold proclamations such as, “I just want you here tonight / Holding on to me so tight.” At the same time, this version also highlights how “All I Want For Christmas Is You” is an aspirational song, an empowering example of someone admitting vulnerability and trying to engender a best-case scenario. The tune puts forth not only an idealized version of Christmas, but also imagines the perfect version of someone’s life.

“Thousands of original Christmas songs have been written in the last 20 years,” Afanasieff told Billboard. “It’s not like no one writes Christmas songs—everyone is trying to get a Christmas song. But for whatever reason ‘All I Want For Christmas Is You’ just became that song. It’s kind of something you never would have thought, and you can’t really explain why, and we feel lucky, because it was the last major song to enter that Christmas canon, and then the door slammed shut. It just closed.

“I’m sure there’s going to be another one; there has to be,” he concludes. “But it has to be the right artist at the right time, the right words and the right melody for the right cultural moment. It became our song 20 years ago, and it just keeps growing and growing.”