Poop organ is a demo in which a short standing wave is created by dropping a piece of plastic sewer pipe (hence the "poop" in the title) on the ground. Different lengths of pipes create a different tone, and an “organ” is created. The group plays a song using different lengths of pipe.
How it Happens
In "Hoot tubes" the standing wave is created by interference formed when air passes through the mesh at the base of the tube. In pipe organ the standing wave is created by the plastic walls of the tube vibrating when the pipe is dropped on the ground.
Standing wave: Unlike a traveling wave (demonstrated in the audience wave, and anti-node jumping), a standing wave remains in the same place and is formed whenever two identical waves interfere with one another while traveling opposite directions.