If you study physics or biology or other sciences, you learn of ideas that are fakes, such as the idea in physics that you can walk on water. These ideas are fakes. In art, there is real art from non-art. It is the way you define art. For example most all of Picasso is nonart for it sheds no light on history.
Art is connected to history.
Music to psychology. The utility is easy to see in something like soldiers singing the melody of Battle Hymn before a Civil War battle. A mood enhancer. I am a scientist figuring out what art, poetry, and music are. Concepts like aethetic are vague.