Expanding upon
Beltane's and responding to
nocodeforparanoia's writeups,
jazz is a musical genre like any other. It is comprised of
structures,
techniques and
instruments. It's not just about
complexity, and just because a musical piece is complex does not mean it is
jazz. Jazz evolved at the onset of the
Harlem Renaissance, coalescing in the murky nights of New Orleans, drawing upon
Appalachian,
folk,
classical European,
African tribal traditions, and
Creole among other things before exporting itself and becoming a cultural marker for African-Americans. Jazz is an existing, definite genre.
The claim of hardcore becoming the New Jazz is a dangerous generalization since hardcore and jazz are separately existing genres, both with their own cultures and styles. Even within both genres, there are multiple schools of thought as to the theory and purpose of their existence. Hardcore bands range from Hatebreed to Boy Sets Fire to The Refused, all varying in lyrical subject, purpose, and musical style and complexity. Just because a hardcore band experiments or plays in awkward tunings or time signatures does not make them jazz.
The importance of lyrics in a song is a difficult subject to approach. It is up to the listener to determine the intent of the composer. It is unfair to listen to a piece with "poor" lyrics, label it crappy music, and tell all your friends when the composer had no intention of the lyrics being something meaningful. In fact, a number of jazz pieces are lacking in lyrical depth but that's ok because the voice as an instrument is what's important. Likewise, some bands prefer the music to be the vessel for the lyrics; it's the meaning of the words that matters.
In conclusion, hardcore and jazz have evolved as two separate entities with defined attributes. If you're looking for new jazz, I would look to the experimental and progressive jazzmen that dabbled in fusion or acid jazz or the emerging European style, the European.
http://www.encyclopedia.com/html/section/jazz_RecentTrends.asp Where I got the info on fusion, acid, and the European