A really smart guy once said "the medium is the message." I've never been able to fully wrap my mind around how totalitarian that sounds but have come to understand it as: "don't forget, the medium communicates more than you think." In light of recent debates, I'd like to proffer another one: "the process is the message." That is: the process by which one creates music embeds information into the fabric of the music itself.
The Classical tradition began as an aural one in the cloisters of the Catholic Church (which at the time was just "The Church"). But with the advent of notation, it quickly embraced the new technology allowing more strict codification and more perfect transmission. Since then, a fundamental rift has arisen between the Classical/written, tradition and the folk/aural tradition. The process has always marked each tradition: for example, it is presumably impossible to create dense, imitative polyphony without writing it down.
While there has always been a mutual influence--from parody masses to Mahler--the two traditions have maintained a comfortable distance. Until today.
In the last 100 years, recording technology has steadily improved, allowing for faster and more "lossless" transmission of sound. Just as film technology changed theater, recording technology has and will change music. My specific interest lies in how it affects how music is created.
After World War II, European artists did everything they could to rebel against the fascism that had wreaked havoc on the continent--that is, anything Romantic, narrative, or populist. Many American composers followed suit but not all. The 1950s explosion of popular music in America had a significant influence a decade later in Minimalism, a language of music heavily indebted to the rhythmic prominence in Rock and Roll and recording technology in general.
Now, a couple generations later, there is debate about whether young (20s-30s) composers are straying from the fold by incorporating elements of pop music. To distinguish them from "real" contemporary Classical composers (even though the Classical language is dead), we have invented the term "alt-classical" (which only looks cool in lowercase).
Same stuff, different century. The balance of power between aural and written traditions has been grossly one-sided, favoring the latter for the last millennium. Now, with recording technology, the aural tradition is finally poised to catch up and surpass (which it did in the 70s or 80s). Fusing the two styles is the only logical recourse for a generation of composers who didn't grow up with "High Art" beaten into their brains.
If you're new to alt-classical, start with its poster child: