Turnipish Thoughts wrote:A perfect cadence will always sound final; the 7th will always lead in to root, the minor third will always sound more dissonant than the major third when in harmony with root, moving a triad chord up or down a half tone in sequence will always sound spooky/magical. These aren't so much things we have culturally decided on, they are things we have discovered about an objective truth, a verity of existence that has substance external to our understanding of it, a physical science.
No no no. This is a faulty view. Harmonic practices are certainly culturally dependent, and Western theory only relates to one set of them. It isn't universal. For example, anyone working with electronic music should understand that pitch is an abstraction. This means that our harmonic system, which deals with pitch relationships, is at least partly arbitrary. There are good physical reasons underpinning the interplay of consonance and dissonance, but this is not something which is universally binding - it's a cultural phenomenon.
Think about this... the Reanissance (about 1400-1600) was a time where people on the European continent decided that 3rds were a consonant interval - extensive use of thirds as a consonant harmonic entity was a trend started by the English, and adopted by the continentals who had to adjust their whole system of tuning to account for them. Before this time, we had a different theory of music, where thirds were (believe it or not) considered dissonant (and pitched very slightly differently). And much, much earlier, the Greeks had a different theory to that. Presently, many different musical cultures use different systems of pitch and follow conventions not well encompassed by the Western system.
There do seem to be some similarities, or fundamental things which re-occur throughout history, in different cultures, and this seems somewhat related to physics - e.g. the pentatonic scale (widely used in folk music from many different parts of the world) is similar in pitch structure to the arrangement of harmonics above a fundamental pitch. But this is a lot less conclusive or constraining than you were suggesting.