Yes, we've all experienced the endless debate on the topic of what is and isn't metal (typically in reference to numetal and metalcore). Anyway, whenever I get stuck in one of these discussions I find my self not very capable of arguing for either side because I can't really explain in words what metal is (it's hard to define a genre that can contain both Behemoth and Blind Guardian). So what is metal? Are there a set of musical qualities that must exist for something to be classed as metal? Are there qualities that cannot exist? Is it just a broad term to describe existing genres that have evolved from the so-called 'heavy metal'? I've heard that metal bands are bands that consider themselves metal bands. So what IS metal?