My current fiction project is The Shoggoth Concerto, a novel set in the same fictive world as my series The Weird of Hali but not part of the same story arc. One of the two main characters is a young mixed-race woman attending Partridgeville State University in Partridgeville, New Jersey -- fans of Frank Belknap Long stories will know already to expect reference to the occultist Halpin Chalmers and the terrifying Hounds of Tindalos -- who is taking her first steps toward becoming a neo-Baroque composer. (The other main character is a shoggoth, but that's another story.) To get the necessary background for the character, I've been reviewing most of the history of Western music, and ran into a very odd detail. 

There were a variety of significant shifts between Baroque music -- think Bach and Vivaldi -- and classical music -- think Beethoven and Brahms -- but one that really stands out is the role of the melody line. In most classical music, as in popular music since then, there's a single melody line over the top of the bass line, and the "harmonic middle" between them -- the other voices that give the music richness. In Baroque music, there were very often multiple melody lines, with the interplay between them creating the harmony. 

The change from Baroque to classical happened right about the time the industrial revolution took off. So at the same moment that our civilization committed itself to the trajectory of industrialism, with its myth of linear progress and its dependence on a straight-line movement of resources to waste, the musical expressions of our civilization shifted from forms that embraced many melodies at the same time, to forms that permitted only one. Blake's comments about single vision seem even more trenchant...