No Way You Know What These Are… Unless You Grew Up Hearing That Sound

The First Clue Is How They’re Worn

Notice the loop at the top.

That wasn’t decorative.

You slipped it over your finger so the two balls hung freely.

Then you swung your hand just right—up and down, rhythmically.

At first, nothing happened.

Then suddenly… clack.

And once you got the timing right, it didn’t stop.