@larsman @mahgister
Prior to my research into the ancient past, I would have agreed with @larsman about the soul. Something like a deep and abiding conscience, which not all people have. Christianity would say, I think, that everybody is born with a soul. Studies of psychopaths would disagree.
As I studied ancient humanity, I found out that art and music seem to define humanity (Homos sapiens). Prior Homos species had the same body structure and just as large a brain cavity, if not larger in some cases. But not until about 60,000 years ago (some might say 100,000--it doesn't make a difference for my argument) we find a sudden burst of creativity out of the Homos genus. Tools, jewelry, art.
From a Darwinian perspective, why would Homos Sapiens waste their time with art rather than finding food and lodgings? How does art help Homos sapiens in our survival? And yet there it is. Jewelry buried in caskets. Cave wall drawings and paintings. What was that all about?
The oldest known musical instrument is a flute made out of an animal's horn from about 43,000 years ago. Most likely, prior to that there were instruments made out of wood and other materials that deteriorate. Like visual arts, music seems to go back to our beginnings, and we must have needed it to give it priority over other endeavors that would add to humans' survival.
I think it's fair to assume that dancing may have gone hand in hand with the music. It is my opinion that people decorated their bodies, played music, and danced to celebrate their existence as part of the universe.
The first deities of which we find evidence are pregnant female figures known as "Venuses." It makes total sense that early humanity saw femals as the creators, because when they saw animals and humans born it was always from females. I won't go into the evidence, but it seems that females were also the first cave painters. There is strong evidence that those first cave painters were shamans and priests.
From what we know of the early feminine religions, they were much different than the later male-dominated religions. Judaism, Christianity, Islam, etc. believe in a male creator who stood apart from, and outside of the universe. The Torah (Judaic Bible) had no godesses, even though literature that influenced the Bible did have many strong goddesses.
Why is this important to the soul and music? The Great Mother (highest feminine goddess) was a part of her creation, unlike the God we know today. She did not exist apart from the universe. So, when people sang and danced to the Great Mother, they sang and danced to the universe and their existence as part of it.
Everything was a part of something. There were no individual souls like we have today. So music was joy on the deepest soulful level. Joy at our existence as well as a deep respect for the universe. And this is how I see music tied to the "soul." Although, I don't see the soul as an individual thing, as religions do today. We all share the universal soul with the Great Mother or whatever you want to call the creator who created by being a part of things, not outside and above things.
I am sure this is different than how you have seen the soul as something that belongs to you. I see it as a collective thing that is to be rejoiced. Since this, I believe, reflects ancient thinking, very early composers could have written with a soul in mind that is similar to what I have just described. And for me, the deepest music is a reflection of this.
