In jazz we think of it as a language. Just like we are all here using the same english words we are all expressing thoughts and ideas that are novel and framed in different ways. And how did we come to get a grasp on this language in the first place? By imitating people who already speak the language. But once we got good enough with imitating we started building a vocabulary of expressions and ways of speaking that are unique to us. Now it is so deeply integrated that it is effortless. To have this conversation, to write all of this out. That's improvisation. So transcription is very important to build a lexicon in whatever genre you wanna play. Once you get a grasp of how other people play you can start pieceing together phrases of your own.
The idea of expectation and subversion of expectation is also a powerful one I think.
Broadly speaking I guess everything is improvised all the time but that doesn't help us build a vocabulary that's meaningful to us and other people.
Surrender is the final step, to give the control up to Music and be the instrument that you were meant to be. Jazz cats know it intuitively, they call it the zone, the flow. They know that the best improv is effortless and they are not doing it, they are not in control, Music is. But that's not the focus of jazz education(which is 90% focus on improving as improvisers). The reason for that is that it doesn't help at all to surrender when you don't know the language. I can surrender all I want that won't make me able to have a conversation in japanese.
