The Hot, mild, and cool cycle
Art genres seem to go through the same patterns. They are born hot, vibrant and full of the energy an act of rebellion demands. Once they become more popular, they turn mild, expansive and sometimes bland. As the genre fades away in popularity, it becomes cool, niche and rational.
It’s a cycle of visceral birth and rational death, like the old adage:
If a person is not a liberal when he is twenty, he has no heart; if he is not a conservative when he is forty, he has no head.
Let’s go back to the jazz age to illustrate the full spectrum: