Jazz: the birth and death of a genre
Over the past nine or ten years, since I've started trying to learn more about jazz, I've noticed that in every online jazz community there's a certain contingent of people who take a hard-line position about the definition of jazz. The argument always boils down to the same essential statement: "jazz is jazz; don't use the name for something that's not already acknowledged [by whom, I'm uncertain] to belong to the canon."
"Jazz is jazz" says nothing. This perspective can refer only to the past of jazz. Excluding other influences and combinations denies the evolution of jazz as an art form. Imagine yourself as a jazz aficionado living in the 1930s. What would you have said, for example, about Miles Davis if you could have looked ahead to the future of jazz? Would you have complained that his music was too far outside the jazz canon of the your era - the 1930s - to be considered "jazz"?
As a musician I certainly want to be aware of the history of music. I've experienced first hand many changes and developments in contemporaneous music and have made a conscious effort (trying to dispel my own ignorance and prejudice) to learn more about music that predates my existence.
I understand that change and uncertainty can threaten the established order. I've caught myself taking an inflexible position against music that I don't intuitively understand or appreciate. If there's one thing that I've learned - over and over, it seems - in my 55 years on this planet, it's that my viewpoint (on anything, not just this subject) is not necessarily shared. I've had to learn - the hard way - to open my mind to other peoples' outlooks regarding "the way things are".
I have to wonder whether disciples of the canon believe that jazz is at the end of its road. Do they believe that the acknowledged master works of today will be appreciated forever? Has everything that's doable already been done? Will anyone take the art form to the "next level" - whatever that may be - or will the genre(s) slowly atrophy to the point where only the "best" works and styles of the past survive in a state of suspended animation, appreciated by stuffy "patrons of the arts" in much the same way that classical music is "enjoyed": in a humorless, insular, passionless, inward-directed contemplation of the "past masters"?
Did you know that in its day (from the mid 1700s onward) classical music was written as incidental music to support social events and theatrical performances? Tens of thousands of symphonies were composed with the expressed intent of being performed on a particular occasion and then forgotten.
Classical composers worked hard to elicit a reaction from their audience during the performance; they would have been appalled by the tight-lipped, clenched-cheek demeanor of today's symphony-goers. The classical composers didn't follow a rule book; they invented musical conventions in order to obtain an emotional response from their audience. The "rules" were derived much later by scholars attempting to decode how the great classical music was written.
We're in the same situation today, I fear, with jazz. In certain quarters there's a need for certainty about what's right and what's wrong; what's jazz and what's not jazz. Certain aspects of the music have been analyzed and codified and disseminated via music schools; students, critics and aficionados pull the past around them like a familiar blanket.
Meanwhile, the people who are making new music, rather than paying homage to the past greats, still call their music whatever they want. Musicians and composers who are creating new music ultimately want to connect with an audience.
Any artist attempting to create something new is looking to push the boundaries established by the past masters. An artist must walk a fine line. If they stay too close to the work that has come before, no one will take them seriously. Likewise, if they don't at least acknowledge the past, then they don't have much chance of connecting with their audience through some shared reference.
In my book, it's perfectly acceptable for an artist to call new music "jazz" even when it doesn't adhere to canon. The expectation is that an open-minded listener having "jazz" interests similar to those of the artist will appreciate the artist's continued development of the art form. If there's not enough commonality, the artist will find out soon enough (through lack of interest from the intended audience) and try a different tack. In any case, the listeners who are inextricably bound to the past will never be part of the potential audience for new music.
 "Musicking", Christopher Small, Wesleyan University Press, 1998, chapter 10.