[kazoocruiser]

Keith, thank you for your well-thought-through-presentation.

I think maybe a good example of what you are explaining might be along the lines of what a Beechcraft Bonanza pilot hears when the two propellers on either side of the plane phase rotationally and acoustically overlap when they are both running independently of each other. Or maybe what a person would hear while standing between two running electric fans in a quiet room.

Acoustic energy fascinates me. Music and sonic vibrations. Resonance and reverberation. If you get near a piano, or actually get to do this, it demonstrates some of what you are talking about.

Push the damper pedal open. Smack the A below middle C, and then listen to all of the semitones, halftones, and octive notes that will sympathetically resonate, while the damper pedal is held down.

If you then hit an E or a C, you will add resonance, as both those keys are part of the natural A major chord.

If instead you smack a note not part of the structure, you install dissonance, like two keys out of tune with each other. Each note is in tune with itself, but not with each other.

Who knew that having a background in Music helps fix engines?