[EbrsaRynleot]

btw.

i believe some music theory can occur in the densities that can live in *harmony* together, like in this case, 4th with 1st and 2nd but not third.

think about music and notes. basic stuff.

let's say i play a c note. if you want to make a very weird and ugly sound, play a c with a c# or b. the half tone between them will have a huge tension sound in it. there is often one note in both of them that sounds louder than the other, and both of them generally stop vibrating faster than other notes that sound good together.

take c with a e or g. these notes have a good harmonic resonance. you can literally feel on a guitar the vibrations going together pretty well. the same rule applies on all of them. some are harmonious with others, and some are not. you can create tension with sound, which will most likely make a sound you'll dislike. i figured out that tensions in sound tend to suppress each other, instead of sustaining themselves for a while.
of course the best alliance you can get in sound is the root and the fifth and the octave.

i may be wrong or not explain it pretty well, but i believe this makes some sense to me, as i know music quite well, and it is quite easy to understand and imagine.