African American history is filled with song and this cultural music, created to underscore the experiences of a people, would consistently morph from one form to another.  With new incarnations would come enthusiast and detractors   alike -- Jazz was no different.

In spite of those who would rail against the 19th century style, it continued on, rising from the roots of Negro spirituals ragtime waltzes and blues structure.  Perhaps it was because jazz, infused within its infectious melodies and slick brightness added a fun element of hope and laughter that was missing from the blues and other popular genres at the time.

There was also a new, spontaneous side to it, as jazz players were prone to improvisation, meaning they could play without a rehearsed ideal of where the music could go.  For this reason, jazz musicians became extremely accomplished and well respected players.

Subgenres

Because the basis of jazz was improvisation, it was only a matter of time before the genre itself splintered into various forms, namely swing, big-band, be-bop, New Orleans Dixie, Latin and Afro Cuban.  In the latter decades, fusions that included rock or pop elements were introduced to the dismay of many purists.  Even acid jazz, which combines funk and hip-hop were placed under debate by those who felt that true jazz contained traditional structures that should not be changed.

Those who embraced the new styles argued that the true spirit of jazz is in its evolution-that Jazz began with improvisation, meaning it could lead anywhere.

In reality, even the older genres of jazz met with these very same debates as those who enjoyed the early manifestations of the genre pitted themselves against anyone who dared trifle with jazzes earlier formula.

Jazz fusion and neo jazz

The wonderful and influential Duke Ellington wasn't even immune from fire, as he met with numerous criticisms from purists who felt that jazz should have limitations. Many of these jazz fans felt his music was too orchestrated to truly be labeled by the free form genre.  Ellington answered these charges by glibly replying that "It's all music!"

Modern day jazz pop performers like Jarreau, Anita Baker and George Benson came under fire in recent history for their pop takes on the beloved style.

To me, these purists are trying to find the devil in the outdated details.

I for one agree with the modern day jazz ideology.  Jazz as a form cannot be contained.  It will always be free of structure, which is the very reason why it was birthed and why it will continue on in its many incarnations for centuries for indeed, it's all music.