The purpose of art is to attain higher states of feeling which include meaning and intrinsic value of what is truly beautiful through the senses. Art may express the way the world is at a given time or how someone feels about the world at a given time. These expressions of the artist may give a valid and true expression of the values, thoughts, and attitudes people have in the times they live in.
Many artists were Platonists. Among them were Michelangelo and Botticelli. Their art depicts various Platonic concepts. For example Botticelli ‘s Birth of Venus depicts a woman standing on a shell which is supposed to be the birth of the cosmos as an emanation from the shell. In various architecture and church art pillars hold the walls of the churches and mosques and the ceiling is in the shape of a dome. The walls and the dome represent the various metaphysical hierarchies from intelligences to the Good, the One, and God, which are different names for the same thing.
The difference between noise and music is that noise is chaotic and music is harmonious. Music expresses harmony while noise brings sounds of chaos.