Music is there to express beauty.
Beauty comes in many forms, and how we interpret it reflects how we look at life.
The greatest beauty comes from not trying to be beautiful, but telling a story of arriving at beauty... music of triumph, loss and return.
This idea of beauty, as a journey, expresses more than written philosophy or pictures can. It is an attitude that unites emotion and logic, an aesthetic power.
This is what all good metal has. All bad metal has ugliness or like Nightwish beauty with ugly structure, goes nowhere.