Animals liking Metal show that Metal objectively makes sense, since it is recognized as natural enough by nature itself. Without completely realizing it, Metal musicians have followed patterns and sounds that have deeper implications regarding natural laws than most of us can suspect.
Basically all rock progressions are 'natural', that is to say they are rooted in the mathematical structure of sound. By the same token all rock progressions are derived from classical music. The more melodic black metal bands are probably even closer to 'natural' sound, but heavily chromatic death metal is mathematically obscure and has no surface relationship with natural laws. The content of death metal music, and really all music making extensive use of chromaticism is elucidated by its overall structure, which requires rational understanding beyond the capacity of an animal. To put this another way, the content, or the metaphysical implications of modal (melodic) music are immediately evident, at least to some degree, and development is an elaboration. On the other hand the content of music like death metal is entirely dependent on the way themes are developed, because the themes are too obscure and fragmentary to have much value in themselves.