"""an order of magnitude more harmonically complex than classical. """
Depends on the classical. There's classical stuff that's harmonically miles beyond jazz music.
Contemporary classical, that is.
Depends on the classical. There's classical stuff that's harmonically miles beyond jazz music.
Contemporary classical, that is.
In any case, your point is well taken. It would be interesting to trace the parallel development of harmony in "serious" music and jazz. (Which, of course, someone has done.)
What's "serious"? What's a "composer"? What's "art"? What's "sound"? And just like any jargon, it depends on the audience with which you're communicating. The more you try to standardize a definition, the more star systems will slip through your fingers.
A famous example is Shakespeare, who was vulgar until the German Romantics discovered him as classic.