If you've ever visited one of the five Disney theme parks around the world, chances are you've heard a continuous loop of the song "It's a Small World (After All)" and found it vexing, says Jason Richards in The Atlantic. The song, written in 1964 by Robert B. Sherman (who died March 4), was calculated to be both easy to sing in different languages and uniquely unforgettable — which may be why it has so often "gotten on people's nerves," writes Richards. "It's a Small World" is "a common 'earworm,' a piece of music that can easily get lodged in the auditory cortex." In this excerpt, Richards explains why the song has become such a bugaboo:

James J. Kellaris, a marketing professor at the University of Cincinnati, has done extensive research on what makes certain songs get stuck in the head. His theory is that music can create a "cognitive itch—the mental equivalent of an itchy back," especially when three qualities are present: repetition, musical simplicity, and incongruity.

No one would argue that "It's a Small World (After All)" isn't simple or repetitive. The word "world" appears 14 times in the 22 English lines of the song....

As for incongruity, one could point to the cheerful young singers of "It's a Small World (After All)"... "Children's music is difficult for grown-ups, a lot of the time. It's really meant to appeal to things that a childish sensibility enjoys," said Carl Wilson, a music critic from Toronto and the author of Let's Talk About Love: A Journey To The End of Taste. "And for grown ups, that can be maddening, especially when you've been exposed to that your entire life. 'It's a Small World' is way better than the Barney song, for example, and the Barney song practically makes adults run screaming from the room because it's so specific to what a toddler likes."

Read the entire article in The Atlantic