In 1966, a songwriter named Dick Holler wrote a straight military ballad, in the mold of “The Ballad of the Green Berets” and “Sink the Bismarck,” about World War I fliers doing battle with German ace Manfred von Richthofen, known to history as the Red Baron. Record producer Phil Gernhard suggested that given the popularity of the comic strip Peanuts, perhaps Holler (who would also write “Abraham Martin and John”) could incorporate Snoopy’s battles with the Red Baron and turn his song into a novelty number. Gernhard offered “Snoopy vs. the Red Baron” to a Florida band called the Royal Guardsmen. They were skeptical about it but cut a demo anyway—and by the end of 1966, their demo, with a few late overdubs in the studio, was a smash hit. “Return of the Red Baron” followed “Snoopy” up the charts early in 1967, and “The Airplane Song,” another novelty, hit that summer.

The Guardsmen considered themselves a legitimate rock band, so they opened their shows with their novelty hits before going on to the stuff they preferred to play: songs by Cream, Jimi Hendrix, Procol Harum, the Stones, and other heavy bands. But their record label, Laurie, preferred that the Guardsmen record what had worked before, pigeonholing them as a novelty act. So in the fall of 1967, when Laurie brought them “Snoopy’s Christmas,” they weren’t enthusiastic. But with little choice, they took it on. (“Snoopy’s Christmas” is credited to Hugo and Luigi and G. D. Weiss, although group member Barry Winslow calls it “pure Dick Holler.”) Group member John Burdett recalled that they worked in the studio with a full orchestra, and the conductor kept trying to change the arrangement because he felt it wasn’t “correct,” so the group threw him out and finished up the recording on their own.

“Snoopy’s Christmas” ended up being a hit for the ages. Radio station WALT, in the Guardsmen’s hometown of Tampa, had helped the band get some early bookings in 1966, and they were the first to chart it, on November 3, 1967. Within two weeks, however, the song was on some of the most influential stations in the country: KNUZ in Houston, KIMN in Denver, KJR in Seattle, KMEN in San Bernardino, WMCA in New York, KOMA in Oklahoma City, WLOF in Orlando, KDKA and KQV in Pittsburgh (both of which would eventually chart it at #1), and KXOK in St. Louis. More stations picked it up as November turned to December, and by the middle of the month, it would have been quite literally impossible to avoid hearing it, not just in America but in Australia, where it was also a monster.

“Snoopy’s Christmas” did not make the Billboard Hot 100, although it did top Billboard‘s special Christmas chart for the entire month of December 1967. It made the main Cash Box chart and rose to #10 for the week of December 30, 1967. KDKA ranked it as the #4 single for all of 1967, behind only “I Think We’re Alone Now,” “I’m a Believer,” and “Happy Together.” “Snoopy’s Christmas” would reappear on Billboard‘s Christmas charts in 1968 and 1969.

The Royal Guardsmen would do Snoopy one more time, with “Snoopy for President” in 1968, although 1969’s “The Smallest Astronaut” is clearly a Snoopy song without mentioning him: group member Bill Balogh says that Charles Schulz, who had been paid a sum of money by the record label before “Snoopy vs. the Red Baron” was released (and who provided artwork for the group’s first album), had told them “no more Snoopy songs.” By then, the Guardsmen had already begun going their separate ways and would break up officially in 1970. As most bands do, they have reformed a few times over the years; in 2006, they recorded “Snoopy vs. Osama.”

Fifty years on, “Snoopy’s Christmas” is one of the holiday’s season’s essential records. It’s satisfying to hear it each year, satisfying in a way that lots of other familiar holiday songs are not. I can’t describe the feeling beyond that; it just is.