Its rise onto the charts comes long after SmartStudy, a Seoul-based company that has produced thousands of children’s videos under the Pinkfong brand, first posted it on YouTube in November 2015. The company remixed it, adding a new beat and melody, in the now-popular version posted in June 2016. It has now been adapted into more than 100 versions in 11 languages, the company said.

The song was helped along by attention from K-pop acts in Korea and spread throughout Southeast Asia before eventually finding its way to the United States in 2018, when a social media challenge invited people to post videos of themselves dancing to the song. Participants included Ellen DeGeneres and James Corden, while Kylie Jenner and Cardi B made references.

It first appeared on Billboard’s Kid Digital Song Sales chart in July, followed by the Streaming Songs chart in November. It also made it to the U.K. Top 40, which is not produced by Billboard, in September.

Making a Top 40 list is far from easy. Jimi Hendrix made it to Billboard’s just once. Wu-Tang Clan never made it.

But today’s charts are different, and often include an eclectic mix of music. Billboard has made a series of changes to its rankings for an era in which viral hits on social media can capture more attention than sustained radio airplay, and consumers download more music than they buy in record shops.