This little girl demonstrates polyrhythms using taps

A school that can do this, whatever price

Most of us can barely pat our head and rub our tummy. This is something else.

Speed a 3 against 2 polyrhythm into the audible range and the ear stops hearing rhythm. It hears a perfect fifth instead, because that musical interval is the same integer ratio of 3 to 2 played fast enough to become pitch.