I still note that not a single person in this thread has posted a link to any music made before about 1957. Wake up, folks; that 40 years of recorded jazz before Kind of Blue, Giant Steps, and the Brown-Roach Sextet didn't just disappear.
If you want to know something about free jazz, modal jazz, and fusion jazz, you need to listen to what those musicians started out playing, which is bebop and hard bop; and if you want to get the bop styles, you need to listen to what those musicians started out playing, which is swing and "trad" jazz.
I'll say it again, if you want to claim that Fats or Art or Roy E. or Benny or Bix or Louis (Hayes, Armstrong, or Prima) or Hawk or Prez or Rabbit or Kid Ory "isn't jazz", you'll be contradicting some people who might have known what they were talking about: guys like Diz Bird Trane Dex Pepper (Adams or Art) McCoy Elvin Mingus Rahsaan and so on, how many names do you want me to list of well-known later jazz players - some of them working in very abstract styles - who repeatedly expressed their debts to and love of the work of the elders who came before.