Heavy metal music
Critics disagree over who can be thought of as the first heavy metal band. Most credit either Led Zeppelin or Black Sabbath, with American commentators tending to favour Led Zeppelin and British commentators tending to favour Black Sabbath, though many give equal credit to both. A few commentators—mainly American—argue for other groups including Iron Butterfly, Steppenwolf or Blue Cheer. Deep Purple, the third band in what is sometimes considered the "unholy trinity" of heavy metal (Black Sabbath, Led Zeppelin, and Deep Purple), despite being slightly older than Black Sabbath and Led Zeppelin, fluctuated between many rock styles until late 1969 when they took a heavy metal direction.
Death metal
War metal (also known as war black metal or bestial black metal) is an aggressive, cacophonous and chaotic subgenre of blackened death metal, described by "Rock Hard" journalist Wolf-Rüdiger Mühlmann as "rabid" and "hammering". Important influences include first wave black metal band Sodom, first wave black metal/death metal band Possessed as well as old grindcore, black and death metal bands like Repulsion, Autopsy, Sarcófago and the first two Sepultura releases. War metal bands include Blasphemy, Archgoat, Impiety, In Battle, Beherit, Crimson Thorn, Bestial Warlust, and Zyklon-B.