I've been learning the C Major prelude from the Bach's Well-Tempered Clavier Book II, and find myself mystified by the intricacy with which the composer weaves found independent voices together. Bach rarely lands on a root position harmony, thereby avoiding a sense of closure, and suspending the harmony into a dense contrapuntal tapestry. The effect is like a building made of clouds- a complete structure with no clearly discernible subordinate shapes. The music floats continuously on, and so as a skeptical composer I have to ask, "how does he do this?." So I reduced the music to a chorale, eliminating the harmonic ornamentation, to see the underlying structure more clearly. And what a structure it is!
The question is now, though, how can I think about structures like these as a improviser/composer? How can I incorporate them into my own musical ideas? The beauty about harmonic structures like this one is that it enables the composer to create a simple "floor" that can be built up and out from, expanding the musical ideas into territory that would, without the "floor" be unreachable, or, non-sensible. This dance with the infinite, and this constant sense of reaching for the unattainable on the strand of a single thread, that makes Bach's music so compelling. Whether or not this aesthetic attribute of "reaching" and "unity" has value in the music of a contemporary composer is a controversial question. But as is clear to me from this analysis, as a means of organizing musical thought, there are few systems as abstract or elegant, that permit both structure and freedom, as the harmonic system.