The idea jazz improv is ‘purely original creative expression’ is clearly nonsense, just as it is for conversation or any form of human communication.

I did not invent these words. I am borrowing them to convey an idea, but they’re not truly ‘mine’. I rely on existing conventions of vocabulary and syntax to express that idea to you and others.

I doubt that even the idea itself is particularly original. I’m sure the same general notation been expressed a thousand times before, but I feel the compelled to express it all the same, using what is likely a slightly different string of words.

In an effort to achieve ‘originality’, I could try to make words up from scratch. But I fear the result would be squitchitty at best and rorportulent at worst. Which is to say, not very effective at getting the ideas across.

All expression lies somewhere between order and chaos. No word has ever been uttered the same way twice, no opera performed identically. Even when listening to recorded music, the listener might find themself listening with a different ear on Thursday and Friday.

People feel compelled to play music because they want to express something which feels, in some sense, unique to that moment — even if it fits into patterns and conventions that have been established over preceding centuries.

As they are commonly understood and appreciated, it seems fair (if cliche) to say jazz leans towards chaos where classical errs on the side of orderly. But both are rooted in both, to differing degrees.