Dancing Rocks

The louder the speakers, the greater the vibration.
Ever had drinks rattle off of the table in a loud bar?
Sound vibrations.
What if the sounds were huge? What could they do?
We built the test facility far out in the desert, miles from everywhere.
The entire floor is a gigantic set of speakers.
Workers pile up boulders on the floor.
The camera system is good, says Control, and we race off to the bunker to perform.
I flip three switches, slowly turn a dial, and the boulders dance on the monitors.
Experiment? What experiment?
This is just for fun.