“Silent Night,” originally “Stille Nacht,” was composed in 1818 by Franz Gruber, based on a poem by Joseph Mohr, says Scot Hanna-Weir, a music professor at Santa Clara University. “The story goes that Mohr came to Gruber with the poem on Christmas Eve and asked him to set it to music for that evening’s mass,” he explains. “The carol was performed that night with guitar because the church’s organ was damaged by flooding.”

Stille Nacht also played a significant role in the story of the Christmas Truce of 1914: a rare moment of peace and humanity during World War I. “We know from soldiers’ letters from the event that Allied and German forces stopped their fighting and sang carols across the trenches,” Hanna-Weir says. “Albert Moren, then in the front-line trenches near the village of La Chapelle d'Armentieres wrote about hearing the song sung by the German forces.”

Originally released in 1857 under the title “One Horse Open Sleigh,” the holiday classic we now know as “Jingle Bells” wasn’t written to be a Christmas song. In fact, according to some historical accounts, the carol made its debut at a Thanksgiving service at the church of one of the composer’s family members. That composer, by the way, is none other than James Lord Pierpont—the uncle of Gilded Age financier John Pierpont Morgan.

He wrote both the music and lyrics. Much of Pierpont’s other work hasn’t stood the test of time. Among his other songs are a number of Confederate anthems during the Civil War, including “Strike for the South,” “We Conquer, or Die!” and “Our Battle Flag!”

“O Holy Night” started out as a French poem written in 1843 called “Minuit, Chrétiens” by Placide Cappeau. It was set to music in either 1843 or 1847, according to competing contemporary sources. The song first gained popularity in France, then made its way to the United States.

In 1855, Unitarian minister and abolitionist John Sullivan Dwight—the former director of the school at the 19th-century Brook Farm Transcendentalist utopian agrarian community in Massachusetts—translated the song to English.

Dwight’s translation included a line that doubled as a political statement in the lead-up to the Civil War. “Moved by its plea for justice—’Chains shall he break, for the slave is our brother’—Dwight’s translation struck a powerful chord in the North, resonating as a symbol of unity and hope,” says Rah Bhatt, an expert in audio and sonic branding and the cultural impact of music.

On Christmas Eve, 1906, “O Holy Night” made history as one of the first songs played in a radio broadcast. “What began as a simple French carol has become a universal hymn, a song of resilience, compassion and profound spiritual reflection for people worldwide,” says Bhatt.

Like many Christian songs, the lyrics to “O Come All Ye Faithful” started out in Latin, when the song went by the name “Adeste Fidelis.” It is thought that John Francis Wade, an English musician working at the College at Douai in northern France, wrote both the words and music to the hymn between 1740 and 1743.

Like “Silent Night,” it also played a role in the Christmas Truce of 1914, says Hanna-Weir. “For the most part, the soldiers on each side volleyed carols back and forth between the trenches, but when the English soldiers started in on ‘O Come All Ye Faithful,’ the Germans joined in the singing to the original Latin text of the carol, ‘Adeste Fideles,’” he explains.

Rudolph the Red-Nosed Reindeer first appeared in a 1939 promotional booklet that the department store Montgomery Ward gave away to children at Christmas that year. A catalog writer by the name of Robert L. May came up with the story of Rudolph, inspired by his own childhood of being an outcast who was smaller and younger than his classmates.

Close to a decade later, Montgomery Ward gave May the rights to his story, and along with his songwriter brother-in-law, he turned the tale of the ridiculed reindeer into a beloved Christmas song. In the hands of famous cowboy Gene Autry, “Rudolph the Red Nosed-Reindeer” became a hit in 1949. The classic stop-motion television special debuted in 1964.

Legendary songwriter Irving Berlin penned “White Christmas” sometime between 1937 and 1939, and out of a catalog of nearly 1,000 songs, it became his most popular. He originally wrote it as part of a Broadway revue of holiday-themed songs, which never came to fruition, but eventually became the basis of the 1942 film Holiday Inn, starring Bing Crosby and Fred Astaire.

However, “White Christmas” made its debut on Christmas Day, 1941, when Crosby sang it on a radio show sponsored by the Kraft Company—just 18 days after the attack on Pearl Harbor. The following year, when Crosby performed for American troops overseas, “White Christmas” was the most-requested song.