In Jazz, improvisation isn't a matter of just making any ol' thing up. Jazz, like any language, has its own grammer and vocabulary. There's no right or wrong, just some choices that are better than others.
Wynton MarsalisThe blues. It runs through all American music. Somebody bending the note. The other is the two-beat groove. It's in New Orleans music, it's in jazz, it's in country music, it's in gospel.
Wynton Marsalis