Improvised music
Improvisation is a very misterious process. It's very hard to actually capture it and divide preprogrammed elements from ones which are new, which are really spontaneous and are taken just from the moment and are the reaction to the things which happen. Improvisation is like a fight. There are many different techniques and combinations, there are things you can learn and practice or even master, but how you use them exactly depends on the partner in the end. And on your mood as well. I think improvisation is never "free". Whatever you do is a consequence of what you bring. But it's never the same either and it never repeats the past. So is it possible to develop? Yes it is. You just have to force yourself. At least a bit.
