In time, the whole world would delight in Snowball’s exuberant jig. Schulz posted a video of the dancing parrot on the shelter’s blog, which someone else—possibly someone in Russia—copied to YouTube. It went viral, earning more than 200,000 views in one week. (Today, the video, which is now hosted on Snowball’s official YouTube channel, has more than five million views). Snowball appeared on The Late Show with David Letterman, Good Morning America, and numerous other talk shows, and starred in commercials for Taco Bell, Geico, and Loka bottled water.

Snowball’s public debut also caught the attention of two scientists at the Neurosciences Institute in La Jolla, California. John Iversen and Aniruddh Patel were interested in the evolutionary origins and neuroscience of rhythm and music. At the time, there was no documented evidence that nonhuman animals could dance—or, in more scientific terms, that they could “entrain” their movements to an external beat. “We saw this video, and it really knocked us out—it was the first time we had ever seen this,” Iversen said. “As scientists, you love these kinds of moments.”

Iversen and Patel tested Snowball in controlled experiments, altering the tempos of his favorite songs and observing how he responded without any training or encouragement. Snowball danced in bouts, rather than continuously, but frame-by-frame video analysis confirmed that he adapted his movements to match the altered beats. Soon after, other studies by separate research teams showed that numerous species of parrots could entrain to a beat, as could elephants. Monkeys, on the other hand, did not display much rhythmic talent in the lab.

The findings seemed to fit a hypothesis Patel had recently conceived: Musical rhythm, he argued, is a byproduct of “vocal learning”—the ability to reproduce sounds one has never heard before. Humans, parrots, and elephants are all vocal learners. Elephants have been documented imitating the sounds of trucks and other animals, and parrots are literally synonymous with mimicry. Monkeys, on the other hand, are stuck with an inborn set of hoots and screams. Patel’s notion was that the evolution of vocal learning in select species strengthened the links between brain regions in charge of hearing and movement, which made musical rhythm possible. In the years following its introduction, the vocal learning hypothesis seemed to fit all the relevant data.

Iversen and Patel’s study of Snowball turned out to be just the prelude to a new concerto of research on musicality in the animal kingdom. In recent years, scientists have tested various species and found evidence that nonvocal learners such as sea lions and bonobos have rhythm too. In parallel, pioneering studies have begun to elucidate how the brain tracks a beat, work that may help corroborate that rhythm is not restricted to the planet’s most loquacious creatures. The new findings suggest that rhythm has a more ancient and universal evolutionary origin than was originally thought. “I don’t think the vocal learning hypothesis has much to teach us anymore,” said Peter Cook, a comparative psychologist at Emory University. “Beat keeping might be rooted in a really old, widely conserved mechanism, which is basically how brains communicate. What is more interesting is why some animals don’t do it.”