Dancing Salt: Vibration Experiment
Simple science.
Cover a jar with plastic wrap, wax or parchment paper and secure with an elastic.
Sprinkle on salt or sugar.
Use a baking sheet and wooden spoon to make the salt dance.
Make sure not to touch surface of table whilst banging!
https://mamadrool.blogspot.com/2017/03/sci-fri-sound-vibrations.html