What Makes Quality Heavy Metal?

It's not the guitars, or the words, or the addition of a flute or other hipster ironic instruments -- it's the soul:

Metal is Romantic art, much as the novel Frankenstein or the opera Parsifal are: discovery of transcendent meaning in life by embracing its struggle and suffering as means to a higher end, an idea beyond material satisfaction or fear. To those who see the greatness of this idea, it is a worldview and a life-philosophy, and metal is one of its voices.

When we say metal expresses this idea, we are speaking only secondarily of imagery and lyrics (which mainstream academics prefer to study because they're easy). We speak of the music and the spirit it evokes. Much like songs can convey sadness, fear, anger or hope, like the leitmotifs of Wagner different impulses are encoded in metal music that together suggest a Romantic worldview.

As art, heavy metal music is unique among popular genres for this viewpoint. What makes sonic art "metal" is its expression of this spirit more than any dogma or musical conceits; after all, other bands have appropriated metal riffs for years but without grasping this idea, much like innumerable Hollywood soundtracks have borrowed from Wagner without capturing his ideal.

When a metal band ceases to make Romantic art and becomes another voice for the easy, non-transcendent answers of life -- material comfort, self-satiation, revengeful morality or simply self-obsession -- it is no longer metal, but an imitation of metal, much like advertising jingles often "sound like" a genre without having its artistry or ideas.

NUSA

Interesting analysis: what makes the music good is its organizing or central principle, because when that is achieved, it's easy to make the music expressive, which is what separates good riffs from dumb ones.