Members of a carnival band participate in a "llamadas" parade in Uruguay in February 2009. (Andreas Stapff/Reuters)

When we call something music, we make a simple declaration: Something sounded in time.

That definition covers everything from four minutes of silence to 15 minutes of marching band to 75 minutes of symphony.

And at the root of that idea, the beginning and ending, is rhythm. Rhythm says: Something sounded in time, maybe more than once.

A new video proposes a different way to think about this crucial concept. It takes rhythm out of the back-and-forth, left-to-right structure that Western music theory suggests we adopt and puts it into something a little repetitive: a circle.

Then, it shows us how this new way of thinking lets us hear musical similarities around the world.

Rhythm’s crazy. A few years ago, I heard an old jazz saxophonist point out that a piano’s tone was like a metronome’s beat: They were both just vibrations in the air, things sounding in time. The only difference between a piano and a metronome is that the piano gets in many, many more vibrations per minute than the metronome did—so we hear it as a pitch.

“A metronome sounds like a pitch to the moon,” he said. “And a piano sounds like a metronome to a hummingbird.”