This is going to sound crazy but maybe it does have a survival reason. In societies where music is enjoyed (all major societies today), music has the capacity to not only gather people but also have them experience a shared emotion or thought. Not only that, but music has the capacity to carry a story through time, from generation to generation, and thus the capacity to carry the morals of that story through time too.
Maybe music is a way to disseminate important cultural information across a population and across time, and the societies that did not have music were weaker (eg. due to less shared morals across the society and across time) and therefore lost when they were confronted in battle by a society with music. If music is used in war to inspire courage in soldiers, perhaps it has a function beyond aesthetics and is actually used for survival, in a literal darwinian sense.
http://www.oxfordscholarship.com/view/10.1093/acprof:osobl/9...
From the abstract: "This chapter suggests that the original function of music is most likely associated with social bonding once group sizes became too large to be adequately bonded using grooming alone. It also contends that music served a natural bridge to language as language became inevitable as a mechanism for group bonding and cohesion."
I imagine a prehistoric tribe dancing in trance around the fire, playing with improvised instruments.
The human experience is so "lonely" - we all are separate entities in desperate need to belong - and sharing a common experience and emotion definitely bonds people. It would help glue a tribe together, which is decidedly a survival advantage. And the poor fella who didn't join in because he didn't care much for music would have been marked as an outcast :-)
This is basically how I, and others, tend to feel when attending goa/acidcore/dnb (that one to a lesser extent though) parties. All together in front of the speakers, just us and the music, then the sun coming up. Pure bless. And that's even without drugs, or at least not a lot, go imagine what it's like with certain substances :P.
I tried hard, but this doesn't work for me at all with more popular/known genres, presumably both because of music and audience, too much people just chatting instead of dancing etc, and also never got that connection with metal etc. Would love to see research on that.
Our world looks and sounds nothing like that. We put an incredible amount of effort into aesthetics. Virtually nothing is 100% utilitarian. Shape, colour, texture, and sound are all considered essential.
None of that has direct survival value, but it clearly has such deep emotional benefits that most people would find it very hard to be happy or functional in a purely utilitarian world.
There is a gray, rectangular building made of cinder blocks not far from here. The lighting is sufficient for all tasks needed, and its heating, cooling and drainage functionality is optimal.
A more recently built structure used for a similar purpose sits a few blocks away. Several pointless curves, colors and contrasting materials were used in its design. Light is allowed in from overly large windows near the roof line, leading to wildly varying amounts of illumination in much of the interior. It does not heat and cool evenly. The landscaping is excessive and requires additional maintenance.
Strangely, construction projects seem to be trending away from the former type of structure and toward the latter.
Which building would you rather work in?
More specific to music, it clearly has a unique value even within art. Multiple directors have said something to the effect that a movie doesn't work until the music is put in.
Music very much creates a culture which is important for group cohesion which has evolutionary advantages.
It seems to me like music has a clear value for survival. Music is a type of cultural transmission (memory technique), and humans do sexually select for musical ability (ask a musician).[1] Groups that sexually selected for the ability to transmit oral knowledge through generations (via memorization, including things like meter, rhythms, melody, and rhyming) probably had a greater chance of survival. Before writing, people stored their cultures' encyclopedias in their minds, which often involved music in some way.[2] Cultures also organize around music, people follow the ideas of musicians, etc. Napoleon made some interesting comments about the active use of music in leadership and group behavior.[3] A prehistoric human with an ability to organize groups through music probably had a higher survival/reproduction rate in general, or at least benefited the group through organizational techniques.
[1] http://journals.sagepub.com/doi/abs/10.1177/0305735613482025
[2] https://www.allenandunwin.com/browse/books/general-books/pop...
[3] "Of all the fine arts, music is the one which has the most influence on the emotions, and it is this influence which the legislator must encourage most warmly. A piece of "moral" music, one by the hand of a master, cannot fail to touch the heart and has much more influence than a good, "moral" piece of writing, which moves the mind but has no effect on our behaviour."
Look at the "haka" of the Māori and tell me you wouldn't be scared facing that.
When I hear someone say "I don't much care about music" it's so hard to understand, as personally I feel it's a direct plug to emotions like none other. I regularly experience frissons when listening to an interesting piece - I've always thought everybody did! - and it can change my mood dramatically and instantly. I always feel I should listen to MORE music, but it's such an all-encompassing activity I can't do much while music's around. Some people fall asleep to music, and my brain instead just goes into (positive) overdrive.
EDIT: an anecdote about frissons: ages ago under the influence of strong psychedelics my frissons turned into multiple intense full body orgasms-like waves of pleasure, and it was clearly related to the music I was listening to, the relationship between instruments and the harmony and movement of dissonant sounds to final resolution. Such an amazing, transcendent experience I'll remember all my life. I've never been able to listen to Funkadelic's Maggot Brain album again after that day.
And all this has no clear value for survival? How did it evolve? Is there anything else we do, apart from appreciating "aesthetics", that has no survival reason?