A few years ago, I dated a young lady who said she believed "Music is the language of the soul". All peoples everywhere have music, no matter their differences in religion, ideals, concepts of law and justice, and so on.
What is it about music, then?
It's not just us humans, either. Although birds don't necessarily make music of their own, parrots (well, psittaciforms generally) will dance to music with a strong beat, and some will even add vocal punctuation in time with the rhythm.
Now, we can't know how nonhuman species experience music. We can't ask them what it's like for them, just see that some of them appear to enjoy it. But for us? Music, like poetry, like the well-turned phrase in prose, winds up our emotions. But it bypasses a lot of the thought that goes into appreciating poetry or prose. It's just direct.
Disclosure: I'm an amateur musician. I have a talent (honed to a skill with practice) for hearing a tune and then reproducing it, more or less accurately, complete with counterpoint. I used to think everyone could do this, but I digress.
Now, on occasion I find myself in need of calming influence, and where I live I'm not allowed to have dogs or anything, so typically I'll go and sit by the 88-key keyboard and play whatever comes to mind. Scraps of classical music? Sure. Video-game music? Quite often. (This is an under-appreciated mode of composition!) And sometimes things just bubble up from my subconscious. This time, what floated up was a soft, repetitive melody in a minor key, with a pensive and melancholy sound to it.
I played it, did a couple of variations, and recognized it as Kingdoms of Rain, by Soulsavers.
So I listened to it, refined my understanding of the composition, transposed it into a key I like better on my piano (it's in C#/Dflat minor, I think? and I moved it to G minor), learned to play it. Haunting and melancholy by melody alone, forget the lyrics. I found it emotionally draining and had to stop.
You know, good music just kind of flows into your ears, bypasses your brain and hits your heart - for me, that's literal, but I'm sure most of you have experienced these emotional lifts or drops from music before. Now, isn't that amazing? It's just a bunch of transient wave patterns in the air, and yet it grips us and affects us so deeply. How does it do that? And why?
I don't have any answers.