8 octaves… 'a 5/4 meter we find, e.g., in Chopin's first sonata'. …yes, I was talking in a General sense…. of course there are exceptions… but do you then wish to assert then that the development of rhythm, meter, … even polyrhythms…. evolved as quickly as the harmonic structure? just asking … Cheers.
Hi themeandvariation,
to summarize the whole development of "rhythm", or "meter" in comparison t
o the evolutionary "speed" of harmonic structure is I think too far a field to be discussed in detail here. And I know far too less, to fulfill such a task.
But we shouldn't forget the exceptional status of Chopin. And there ARE for example smaller deflections, which are matter of "feeling" in his works, we call this "rubato", and somebody, who was asked to describe what "rubato" is, answered like this: "Imagine a tree, with its leaves slightly moving by the wind, and behind these leaves, there is the sun, shining her rays of light through the moving leaves..and the glittering you experience then, that's rubato!"
We have moved, as we can see, from "exactly written" things to things which come from the inner feelings or from pictures we imagine. And we can add a very very complex thing, for which Chopin is unique since in him there are concentrated the aforementioned factors valid, plus this very complex one, which is known as
"Zal". It's some kind of "melancholy" that's very special.
It should be clear that overacting in these points, while playing Chopins music, could lead to criticism.("uuuh....toooo much rubato.." etc).
Performers did their part, too. They (especially Cortot, and Paderewski) made use of something we would call "asynchronous touch", which some people like, and others not.
We should inspect carefully. That's what I believe in.
But historical evolutionary summaries I cannot give. Sorry.

Cordially, 8_octaves!