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.
Unblack metal
The 1970s occult boom influenced many early heavy metal bands lyricwise. In the early 1980s, several bands dealt such themes in a more extreme manner, including Venom, Mercyful Fate and Bathory. During the mid-1980s, heavy metal music divided into many subgenres, and black metal emerged as one of them, taking its name from a Venom album of the same title. In the 1980s, the term was imprecise with regards to musical attributes, simply referring to all metal bands with Satanic lyrical themes. Although Christian metal bands had existed since the late 1970s, a clear contrast with black metal occurred in 1984 with the doom metal band Trouble who released the Bible-based album "Psalm 9". Metal Blade Records marketed them as "white metal" as opposed to black metal. Singer Eric Wagner has explained that "back in the early 1980s, all the metal was kind of Satanic," and he has implied that Metal Blade (or the owner Brian Slagel) actually invented the term in the first place: "I think it was more like Metal Blade trying to be cute or something, with everything being called black metal, so why not call us white metal, which is a bunch of crap." While there were Christian extreme metal bands in the late 1980s and early 1990s, Christian black metal likely did not exist until 1994.