What's your favorite Christmas carol? Maybe it's Burl Ives' "A Holly Jolly Christmas," or Brenda Lee's "Rockin' Around the Christmas Tree," or if you're like the majority of Americans, it's "All I Want For Christmas Is You" by Mariah Carey. You may not even realize it, but there are some key elements to these tunes which may have helped them rise to the top of the holiday charts. In an attempt to produce "the happiest Christmas carol" of all time, scientists were called in to identify these elements and help singers and songwriters create some new holiday magic.

Musicologist Joe Bennett, vice president of academic affairs at Boston Conservatory At Berklee, has done extensive research on topics such as the psychology of songwriting and forensic musicology. Over the past year, Bennett was asked to help out with a commercial research project that would be used to create a happy new holiday tune.

To accomplish this mission, Bennett did a deep dive into the 200 most popular songs streaming on Spotify during Christmas week in 2016. He analyzed each song's musical key, time signature, tempo, singer and lyrical theme. Here are the top 10 songs that made Bennett's list:

  1. "All I Want for Christmas Is You," Mariah Carey
  2. "Last Christmas," Wham!
  3. "Fairytale of New York," The Pogues (feat. Kirsty MacColl)
  4. "Merry Christmas Everyone," Shakin' Stevens
  5. "It's the Most Wonderful Time of the Year," Andy Williams
  6. "Do They Know It's Christmas?" Band Aid
  7. "It's Beginning To Look A Lot Like Christmas," Michael Bublé
  8. "I Wish It Could Be Christmas," Everyday Wizzard
  9. "Step Into Christmas," Elton John
  10. "Wonderful Christmastime," Paul McCartney

Bennett found that the most popular Christmas carols were sung in a major key with an average tempo of 115 beats per minute. They made reference to Santa, snow, home, peace and love, and often had the sound of sleigh bells in the chorus. Bennett also identified what he called the "Bublé effect," which made reference to the fact that singer Michael Bublé had 10 songs which appeared high up on the list thanks to his 2011 album, "Christmas."

Songwriters Harriet Green and Steve Anderson, who have written tunes for Kylie Minogue and Britney Spears, used this "formula" to create what they hoped might become the world's happiest Christmas carol. The result, which was recorded by the London Community Gospel Choir, is "Love's Not Just For Christmas." It's not sung by Bublé, but it does have sleigh bells in the chorus, an upbeat tempo, 21 references to Christmas, and all of the other key elements to hopefully make Christmas carol lovers happy.

"Love's Not Just For Christmas" has been released on YouTube and can be downloaded and streamed on Spotify. And science nerds who want to know more about Bennett's research can check it out right here.