The Greeks were awed by Pythagoras' discovery that harmony is ultimately a matter of mathematical proportion. The Greeks took this as proof that beauty is not a matter of taste but a characteristic of reality. The interesting, on the other hand, is highly individual. As such it has no bounds. Given the perversity of the human heart most anything can and does become interesting.
Modern art is a study of the possible, the new, a study of pure creativity.
This exploration of what has not been, has its basis in freedom from prescribed universal categories. Jazz can be said to be the paradigmatic modern art. Every presentation is a happening, a new creation, it is governed only by the interesting. This aspect of unfettered play governed only by the fascination of the moment, the attraction of the sensation, can be seen in dance, painting, architecture, poetry. Modern literary criticism exhibits the change from discovery to creation.