Here is a fingering pattern from Chick Corea, used in Autumn Leaves. In this line Chick is repeating a 4321, 4321, fingering pattern and selecting certain notes to match up. I would say this line is more about a texture rather than focusing on specific notes. When you get to the level these pros are at its more about release and expression rather than thinking of notes. I’m sure in this moment Chick was expressing whatever he wanted by using any notes that happen to fall below his fingers. He is not purposefully thinking, “Okay I’m going to use the b13, then go to the 9 here.” In order to truly begin to improvise freely you must shut your mind off, play any notes you like and play them with confidence! Let your soul and heart do the talking!