One easy case can be attributed to the improvisational nature of jazz - it is hard for the average listener to predict where a solo is going, how a pianist is g

One easy case can be attributed to the improvisational nature of jazz - it is hard for the average listener to predict where a solo is going, how a pianist is going to voice their changes with their left hand while operating in another separate but related space with their right hand. I can't speak to to technical strictly music theory definition of jazz, especially given that jazz now is really just an umbrella for myriad sub-genres, but from my experience the beauty of jazz is that the resolution is not predictable, and more often than not it may make one feel vulnerable, or sad. See classics like Miles Davis, Bill Evans, or for someone alive today, Dr Lonnie Smith.