Harmonic sounds, frequencies and the physical correlations behind it, psychoacoustic influences and natural vs cultural imprints for a sense of musical harmony

[Master Mi]

For some time now, I have been trying to answer questions like these for myself, questions that may have a much deeper background than mainstream music theory can explain.

But maybe there are some advanced experts amongst the OCR community who have studied these topics for a much longer time and who can respond to this topic or to some of my questions:


1) What kind of mathematical or physical influences decide if two or more acoustic events (sounds) with different waves (energy, frequencies, amplitudes) sound harmonic or dissonant to us.
And how do these waves interact and "melt" with each other into a new wave (perhaps by means of an mathematical example concerning frequency, amplitude, time, phase behaviour, stability/duration or degradation of a wave etc.)?

Are we at all able to perceive different tones with different but simultaneously arriving frequencies separately - or do we perceive them as one new frequency?

Can there actually be such a thing as pure tones with pure frequencies in nature?
Or do we always hear a mix of many different frequencies with more or less present frequencies in it?

...

Maybe, I could use this knowledge it for a deeper understanding of harmonic and dissonant chord progressions.


2) In nature or our daily life we are permanently surrounded by a lot of different frequencies and energies.

A... We as human beings often like the sound of a gentle breeze of wind, the ripple of water or the song of a bird.
B... On the other side, we often don't like the sound of road noise, the sound of a gnat, the sound of a hornet or the sound of a fingernail scraping along the chalkboard.
C... And we might even fear the sound of a gunshot, an earthquake or a thunder.

The last case (C) could be easily exlained by the large energetic force behind those loud acoustic events which we fear because we sense that the big energy behind these things might harm or even kill us.

But what 's about case A and B.
Do we like or dislike these events more because of the loudness (which is obviously related to the amplitude), the frequencies or (a possibly dissonant) alternation of frequencies, or maybe because of something else?

Are we born with some kind of natural instincts from which we know what kind of sounds we can trust, which sounds we like and which sounds we don't like?
Or is it much more some kind of behaviour that depends on our cultural imprint, our upbringing and our individual experiences?


3) In our western occidental tonal system, 12 notes/tones form the basis, which continuously "repeat" or approximate each other in different octaves in a certain tonal similarity.

If we start from a certain note (like for example the C with 32.703 Hz), this frequency will always double from octave to the next higher octave in a rather exact way (for example towards a next higher C with a frequency of 65.406 Hz)...

... while the distances of the neighboring notes within an octave rather resemble only a slightly logarithmic, almost straight-line function.

https://pages.mtu.edu/~suits/notefreqs.html

What were the reasons for establishing exactly this kind of a tonal system - why 12 semitones and why exactly these frequencies like 32,703 Hz - and not just straight 33 Hz, for example?

I mean...
I guess, I couldn't even tell a too big difference between 35 and 40 Hz, or let's say between 261,63 Hz and 270 Hz.
Not sure, if the people back then even had the necessary tools to exactly measure frequencies of acoustic events that roam through air (or let's say which "are transmitted by colliding air molecules").

But I'm sure, it has to do with sizes (like different lengths) of acoustically resonating materials like a string.
And why do we perceive octave jumps of notes much more as similar acoustic events - and not as different or new acoustic events?


Is there a natural and more understandable base behind exactly this classification of notes and frequencies?


And my last part of this question (which might already be answered together with the previous question).

Would it be possible to create another, let's say a much more decimal tonal system - a tonal system with 10 basic tones like the following one?
And would it sound good to us or could we get used to it over a long time?

Let's create one like this with the following frequencies:

note        frequency (Hz)
------------------------------
A1                 10
B1                 20
C1                 30
D1                 40
E1                 50
F1                 60
G1                70
H1                 80
I1                  90
J1                100
A2               110
B2               120
C2               130
D2               140
E2               150
F2               160
G2               170
H2               180
I2                 190
J2                 200
A3                210
...
... etc.

Or would it lead to the death of human music, to the death of human ears or would it just be music only robots and machines could understand, love or at least process without crying rusty metal tears?

Edited March 15, 2022 by Master Mi