Music fans in 2019 are gobsmacked that the No. 1 song in America is not only a Christmas song but a 25-year-old recording: Mariah Carey’s holiday perennial “All I Want for Christmas Is You.” Even more amazingly, it’s the first Christmas song to top Billboard’s Hot 100 in 61 years, since “The Chipmunk Song” in December 1958. This leads to so many whys: Why were there no Christmas No. 1s for six decades? Why didn’t ’60s, ’70s, and ’80s holiday classics like “Christmas (Baby Please Come Home),” “Feliz Navidad,” and “Last Christmas” become Hot 100 hits? Why did Carey’s classic not chart in 1994, when it was released—and why did it only start charting in the 2010s and seem to get more popular every year this decade?

In this special holiday edition of Hit Parade, we answer all of these questions and explain how virtually everything had to change about the music business for Mariah’s Christmas chestnut to reach No. 1, from Billboard chart rules, to digital music technologies, to even the tragic passing of a fellow music diva. It all combined to give Carey her incredible 19th No. 1 on the Hot 100—just one chart topper away from the Beatles.

Podcast production by Justin D. Wright.