Actually, great composers such as Beethoven and Bach and Chopin had very definite ideas about what emotions are evoked by certain keys. They even argued about it with their peers. Music is not something that is reducible to mere quanta and waves and frequency. You all are missing the human part. Sorry, but it's true.
Yes, choice of key is one of the tropes that is useful when composing a song's "plot".
> Music is not something that is reducible to mere quanta and waves and frequency.
That's my point; interesting aspects of a song are not derived from specific sounds (and their frequency/etc). Those are the atoms that can be used to create the larger plot.
While it is possible to reduce music to the frequency and timing of its atomic structure, it's similar to analyzing the phonetics of speech or the glyphs of text in isolation. A low level perspective may be useful, but misses the larger structure we call a "song" or "essay".
That, and they didn't all necessarily use a pure Equal Temperament, either. Different temperaments can give more distinct feelings to certain keys more so than the modern equal temperament. (Note: I used to tune pianos.)
Music is waves and frequency. Music appreciation is what you are describing. And appreciation is very dependant on culture. That is why Bach is not (as) appreciated in certain cultures.
Just like photography. Why is one photograph more meaningful than another? it has nothing to do with photography, per se, it has everything to do with the culture of the person doing the appreciation.
There is a link between the two, between creation and appreciation, and those who understand it generally fare better. But it is not required to be a musician, or a photographer or a poet or anything really.
Sound is waves and frequency. Music is a collection of sounds arranged in a specific sequence.
> Music appreciation is what you are describing. And appreciation is very dependant on culture.
Music relies on various "tropes" to construct a narrative. This includes the choice of key/scale (or none at all), ideas about timing and harmony, etc. These "standard parts" of music are usually from the local culture, just like how a play or movie will use standard character archetypes ("tropes") that are culturally derived.
"music is waves and frequency" in the same way that "spoken language is waves and frequency"---not very usefully. I think bringing in" appreciation" muddies the waters.
