As with any other type of music that has been around for decades (ie. rock or jazz) there is now very little in common between the heavy metal of Black Sabbath and the bands of today. Some are known for their theatrics rather than the quality of their tunes (ie. Gwar), other can be considered authentic virtuosos for which labels are rather confining (like Tool and any of Maynard James Keenan’s fronted musical projects).
However, definitions can still help make sense of the many evolutions within this style, and can give the recent listener a map to understand what kind of features they could possibly love the most. So, here are some of heavy metal’s most important sub-genres:
- Doom Metal: derived directly from some of Black Sabbath’s early works, doom metal features a much slower tempo, lower tones and usually lyrics that allude to apocalyptic scenarios. Many notable bands in the scene are considered doom: Paradise Lost, My Dying Bride, Celtic Frost are among them.
- Speed Metal and Thrash Metal: when the tempo in the heavy metal song is particularly fast, listeners are possibly close to a speed or thrash metal band. Metallica fall in the first category: although abrasive and aggressive, their songs, even at the early stages of their career, were never devoid of a melodic structure; with thrash metal, instead, hardcore punk is an influence as much as classic metal, and the songs are harsher;
- Alternative Metal: with the emergence of singularly talented bands starting from the Eighties, which were obviously into heavy riffs and drums but were dramatically far from the style of classic heavy metal bands like Iron Maiden or Black Sabbath made it necessary to create a distinction. These “alternative” groups were combining elements of heavy metal with other styles (like jazz or rap) or with unconventional song structures. Among them are Alice in Chains, Faith No More or Helmet;
- Nu Metal: born in the late Nineties-early Oughties from the inevitable crossover between hip-hop and heavy metal, it’s mainly an U.S. phenomenon that caught the interest of the media as well as entered the charts, as opposed to other sub-genres which were never as mainstream. Limp Bizkit, Disturbed, Papa Roach were among the first bands mixing the two styles, whereas other bands initially regarded as nu metal include Korn, Linkin Park or Slipknot: they’re still active but their sound has dramatically evolved.
- Progressive Metal: another instance of heavy metal fusing with another genre, in this case progressive rock. Some argue that progressive rock was progressive metal from the very beginning, due to events like Tony Iommi from Black Sabbath being a member of Jethro Tull, or the unclassifiable output of such bands like Rush. Tool can be considered one of progressive metal’s most famous bands.