I made a website that describes natural harmonic (just) tuning systems: http://just-tunings.info/learn http://just-tunings.info/learn I do need to add a secti

I made a website that describes natural harmonic (just) tuning systems: http://just-tunings.info/learn http://just-tunings.info/learn I do need to add a section on cultural consonance/dissonance but.. Octaves are not cultural. Resonance is not just an aspect of music or even animals, but literally everything in nature that makes sound. Dropping a rock in water will create sound, and frequencies that resonate with each-other will stick around longer than those that fight, teaching us that these sounds belong together. An octave is the simplest possible relationship between two frequencies, and it can be heard in almost every natural sound imaginable. We learn they belong together from almost every sound we hear. As an aside, western tonality uses the twelfth root of 2 because if you just start hammering randomly on those tones, they'll get along extremely well regardless of whatever the biggest bassist vibration is. The big bassy frequency being the one that every other frequency needs to get along with (harder than it sounds). It's sort of a fudgy form of relativity that allows things to vibe together mostly, but not perfectly.