Jazz was, once upon a time, 4 things:

  1. Improvisation (the creation)
  2. The Blues (the content)
  3. Swing Rhythm (the pulse)
  4. Joy (the feeling)

Innovating jazz expanded one of those scopes.

No improvisation? That’s just classic swing (Frank Sinatra, Big Bands).

I different sort of Blues? Other base music with deep comfort, familiarity, and meaning? That’s world jazz (Hiromi Uehara, Jorge Luis Pacheco, Tigran Hamasayan).

No swing rhythm? That’s Rockabilly and Rock n' Roll, R&B and Modern Gospel.

Swapping out the feeling of joy? That’s cool jazz, modal jazz, smooth jazz, hard bop and free jazz.

Jazz isn’t only what you make it. But most modern forms of music have, at least, a little jazz in them.