I was wondering the historical origin of the diatonic/chromatic scale and how it ended up looking the way it does now in our equal temperament system. And whats the difference between chromatic and diatonic from a historical point of view? I've read that the chromatic scale is relatively recent but I've also read that the ancient Greeks used something called chromatic tetra-chords if I have not completely misunderstood.
I would love it if someone could give me an overview of historical events that led us to the diatonic/chromatic scale.