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.
Heavy metal music
The origin of the term "heavy metal" in a musical context is uncertain. The phrase has been used for centuries in chemistry and metallurgy, where the periodic table organizes elements of both light and heavy metals (e.g., uranium). An early use of the term in modern popular culture was by countercultural writer William S. Burroughs. His 1962 novel "The Soft Machine" includes a character known as "Uranian Willy, the Heavy Metal Kid". Burroughs' next novel, "Nova Express" (1964), develops the theme, using "heavy metal" as a metaphor for addictive drugs: "With their diseases and orgasm drugs and their sexless parasite life forms—Heavy Metal People of Uranus wrapped in cool blue mist of vaporized bank notes—And The Insect People of Minraud with metal music". Inspired by Burroughs' novels, the term was used in the title of the 1967 album "Featuring the Human Host and the Heavy Metal Kids" by Hapshash and the Coloured Coat, which has been claimed to be its first use in the context of music. The phrase was later lifted by Sandy Pearlman, who used the term to describe The Byrds for their supposed "aluminium style of context and effect", particularly on their album "The Notorious Byrd Brothers" (1968).