It played a major part in western philosophy (Pythagoras and Plato), where it was hypothesized that a mathematical harmony pervaded the cosmos. The first empirical -- even scientific -- hypothesis testing investigated this idea [0] using proportional lengths of string and the thickness of bronze chimes. Contemporaneously in China, both Confucianism and Daoism treated harmony as an underlying moral/aesthetic principle. The union of moral and aesthetic harmony was described in the thesis of Francis Hutchison, who was both Adam Smith's doctoral advisor and one of the biggest philosophical influences on the American founding fathers. See for yourself! [1]

Harmony is not sameness -- it is diversity in unity. This is a key insight in both Eastern and Western philosophy. In the West, the connection to the mathematics of the harmonic series doesn't appear to be coincidental (harmonies consisting of notes that share harmonics) -- although I'd challenge anyone to make sense of it all! My point here is that there is a story worth learning more about. I'd argue that we need guiding philosophical principles -- and it is awfully nice that there is a scientific one that underpins some of the largest societies on Earth:

* The official principal objective of the Chinese government is the creation of a "Harmonious Society".

* The official motto of the EU is "In varietate concordia"

* The traditional (although unofficial) motto of the USA is "e pluribus unum"

* The official motto of Indonesia is "Unity in Diversity"

* And now this from Japan!

Not to say that these governments are necessarily aware of this history, but only that these ideas are very old, very core and very unifying.

[0] Barker, A. (2007). The science of harmonics in classical Greece. Cambridge University Press. [1] Hutcheson, F., (1729). An inquiry into the original of our ideas of beauty and virtue: in two treatises. I. Concerning beauty, order, harmony, design. II. Concerning moral good and evil.