why are so many christmas songs in f?

When I was a churchgoing fifth grader, I signed up to be in the Christmas Eve service choir of angels. Signed up, not auditioned, because they just took anyone. I believe there were twenty of us — all girls — and we all sang the exact same notes, regardless of vocal range. It was not prestigious. And then I didn’t even make it all the way through the service, because the spotlight — sorry, the star that led the three wise men to baby Jesus — shining on us was so bright that I felt like I was going to pass out. And I didn’t want to pass out, because I used to be tall, so they put me on the highest tier of the risers. I had to turn around and carefully jump down during “We Three Kings” and sit in the choir room with the lights off for about ten minutes to recover. In sixth grade, I signed up to read New Testament passages aloud instead.
All those ill-fated angel choir songs are still burned into my brain from the weeks of rehearsal, and we sang a disproportionate number of them in the key of F major. I think the simplest explanation is that the choir director decided it was the best fit for the average vocal range of fifth grade girls, but the more I think about it, the more I’m convinced it was part of a larger pattern. Or at least, I want it to be.
Some of the most recognizable Christmas music of the twentieth century is Vince Guaraldi’s 1965 jazz soundtrack to A Charlie Brown Christmas, and Guaraldi arranged a lot of traditional songs in F. “Hark! The Herald Angels Sing” is, like my Christmas Eve service repertoire, performed by a choir of young children, so I suppose you can chalk it up to their median vocal range. Natalie Sarrazin, associate professor of music at the State University of New York at Brockport, and author of Music and the Child, claims the average range of fourth-sixth graders is B♭ to E, with “the strongest notes […] right in the middle of their range, around pitches F and G.” So you’re obviously going to want a key where the performers can hit the tonic note (F) really well. And incidentally, F is one of the only two major scales that includes both B♭ and E! (Since Sarrazin didn’t specify, I reached out to a college friend who teaches music, and they clarified that this would be B♭3 and E4.)
But not all Christmas music is vocal. When I was — one more anecdote, sorry — when I was in first grade, right before I flunked out of piano lessons, I was learning an extremely rudimentary arrangement of “Go Tell It On The Mountain” for a recital. (I did not perform at the recital.) But you’ll never guess what key my teacher had me practicing it in! And I find this perplexing in hindsight, because the method she used to attempt to teach me piano initially eschewed the white keys and focused on sharps and flats. (The F major scale is mostly white keys, with the exception of B♭.) I’m not in contact with that teacher anymore, but if I was, I’d ask her why she didn’t teach me the song in B or D♭ or G♭, since I theoretically would’ve been more comfortable there. Could it perhaps have had something to do with F major’s inherent Christmasness?
Guaraldi’s arrangement of “O Tannenbaum” has not a vocal to its name, yet it also spends most of its runtime in F. Maybe this is to match the other songs in F that do have vocals? Hell, even the scene where Lucy badgers Schroeder into playing “Jingle Bells” on his toy piano has the song in F. Twice! It’s not until he plays it in E at the high end of the keyboard does Lucy deem his performance sufficiently Christmassy. This is because she’s insane.
Okay, what about instrument tuning? I know a lot of brass instruments are tuned to B♭, and the B♭ major scale has six of seven notes in common with the F major scale. E♭, the fourth note of the B♭ scale, is the flat seventh of F, making it ideal for jazz. Hey, what genre was that Guaraldi album again?
I watch a lot of music YouTubers who are actually educated and know what they’re talking about: Mic The Snare, Charles Cornell, 12tone, Adam Neely, and David Bennett to name a few. A couple years ago, Neely responded to journalist Adam Ragusea’s extremely contentious theory that minor iv6 chords (alternately, minor ii half-diminished seventh chords) are the irrefutable mark of Christmasness, which is how the question got on my radar. Neely was kind of dismissively like, “The real answer is sleigh bells,” and then a few years later, Bennett put out his own video about how sleigh bells are a relatively new phenomenon in Christmas music, and the real reason behind the Christmasness of Christmas songs is simply the fact that we only listen to them around Christmas, and thus associate them exclusively with the holiday.
Neuroscientist Brian Rabinovitz echoed Bennett’s theory while serving as a visiting lecturer at the College of William & Mary in 2017, and then proceeded to call me the fuck out: “Our brains are hardwired to find satisfaction in charting patterns, even if they’re a little different than what we have heard before — and that sense of satisfaction is primal.” I’m used to Christmas music being in F. So when I hear an old standard performed in F, I go, “HA!” and then get to feel like a genius. But I’m not a genius. It’s just an Occam’s razor.
On the other hand, I wouldn’t associate Christmas music with F major if so much of it weren’t in F major. I resume my quest.
I should clarify that not all songs in F sound Christmassy. I have a whole playlist of F major songs that bum me out, because I think it’s an inherently sad key, and I assure you, nothing about “Bleeding Love” or “No Surprises” evokes thoughts of the Jesus Born holiday. But a lot of Christmas songs sound off to me if they aren’t in F. All of these, for example:
“Hark! The Herald Angels Sing”
“O Tannenbaum”/“O Christmas Tree”
“Jingle Bells”
“Go Tell It On The Mountain”
“We Three Kings”
“O Little Town of Bethlehem”
“Angels We Have Heard On High”
“The Twelve Days of Christmas”
“Once in Royal David’s City”
“The Little Drummer Boy” (and Guaraldi’s interpretation, “My Little Drum”)
“Deck the Halls”
“We Wish You a Merry Christmas”
“O Come, All Ye Faithful”
You’ll notice that these are all traditional songs. If a piece is less than a century old, I tend to prefer it in the key of its most prevalent rendition. Some examples, and their non-F keys:
“Santa Baby” by Eartha Kitt (D♭)
“White Christmas” by Bing Crosby (A, the key of yearning)
“All I Want For Christmas Is You” by Mariah Carey (G)
“Wonderful Christmastime” by Paul McCartney (B)
“Last Christmas” by Wham! (D)
“Christmas (Baby Please Come Home)” by Darlene Love (E♭)
“Rockin’ Around the Christmas Tree” by Brenda Lee (A♭)
“Feliz Navidad” by José Feliciano (D)
“Christmas Wrapping” by The Waitresses (A)
“It’s the Most Wonderful Time of the Year” by Andy Williams (D, E♭)
“Happy Xmas (War Is Over)” by John Lennon and Yoko Ono (A, D)
“Do They Know It’s Christmas?” by Band Aid (C)
If I may be so controversial, I am partial to the first list. I don’t really like Christmas, so when a Christmas song is in the key I associate with sadness, I feel seen by it. If someone’s out here in D or G going, “WHOOOO CHRISTMAS FUCK YEAH I LOVE CHRISTMAS,” I start longing for the heat death of the universe. The only way to make Christmas music tolerable is to imbue it with melancholy.
Wait, oh my god, I think I may have figured it out. Traditional hymns about the birth of Christ are intrinsically bittersweet, because we know something not chill is eventually going to happen to him. Secular Christmas songs don’t have a sword of Damocles. That’s how Jesus died, right?
SO. I guess it’s that, plus the effect of brass instrument tuning on jazz, plus the average tweenage vocal range. I’ve cracked it. That’s the right answer, and it’s settled forever, and you must cite me whenever the topic arises. Tell the naysayers I sent you personally.

The reason I’m being such a little shit about this is because I learned something really disheartening during the research process: Adam Ragusea, who posited the Christmas chord theory, was harassed incessantly over a tiny mistake he made when explaining it to Vox. In the video I’ve linked, he describes the disproportionate amount of backlash he was still getting in 2020, half a decade after “Chordgate.” Leave him alone????? He has a degree in composition, which is much more than I can say about myself, and he explained his thesis well. Vox oversimplified it in an attempt to provide a definitive answer, when it’s really just one of many. What sounds Christmassy to one person might not sound Christmassy to another. If this credentialed expert is getting crucified (that might be how Jesus died, now that I think about it) over an intriguing, albeit technically unprovable hypothesis that he did not have to share, then there’s no point in saying anything about music theory ever.
I fully admit I’m an amateur, and I mean that both in the modern sense, and the word’s original definition. I love to observe patterns (my brain is hardwired to find satisfaction in it, according to Rabinovitz) and theorize about what they might mean. And the meanings are usually pretty esoteric, so I’m always curious to see if any of them resonate with other people, particularly those who are formally educated and coming at music from a different angle.
Ragusea is a food YouTuber now, and I love that for him, but I’m sad that he was chased out of the music theory game despite his clear passion for it. I don’t even particularly agree with his Christmas chord hypothesis, but I’m glad he wanted to share it. It made me want to share mine.