According to Aniruddh D. Patel -- as interviewed here -- the fact that this bird can dance is quite impressive. And to really see if the bird was responding to the beat of the music, scientists altered the tempo of the music over 10 times to see if Snowball -- that's the bird -- would adapt to the changed beat: he did!
Apparently, cats and dogs do not do this. Just parrots.
So Patel speculates:
What do humans have in common with parrots? Both species are vocal learners, with the ability to imitate sounds. We share that rare skill with parrots. In that one respect, our brains are more like those of parrots than chimpanzees. Since vocal learning creates links between the hearing and movement centers of the brain, I hypothesized that this is what you need to be able to move to beat of music.And for grant-seeking academics forced to use euphemisms, he also tells this story:
One of the founders of this field, Dr. Robert Zatorre, before 2000, he never used the word music in a grant application. He knew it would get turned down automatically because people thought this was not scientific. Instead, he used terms like “complex nonlinguistic auditory processing.”