Black Sabbath in the context of "Music of the United Kingdom"

Heavy metal (or simply metal) is a genre of rock music that developed in the late 1960s and early 1970s, largely in the United Kingdom and United States. With roots in blues rock, psychedelic rock and acid rock, heavy metal bands developed a thick, monumental sound characterized by distorted guitars, extended guitar solos, emphatic beats and loudness.

In 1968, three of the genre's most famous pioneers – British bands Led Zeppelin, Black Sabbath and Deep Purple – were founded. Though they came to attract wide audiences, they were often derided by critics. Several American bands modified heavy metal into more accessible forms during the 1970s: the raw, sleazy sound and shock rock of Alice Cooper and Kiss; the blues-rooted rock of Aerosmith; and the flashy guitar leads and party rock of Van Halen. During the mid-1970s, Judas Priest helped spur the genre's evolution by discarding much of its blues influence, while Motörhead introduced a punk rock sensibility and an increasing emphasis on speed. Beginning in the late 1970s, bands in the new wave of British heavy metal such as Iron Maiden and Saxon followed in a similar vein. By the end of the decade, heavy metal fans became known as "metalheads" or "headbangers". The lyrics of some metal genres became associated with aggression and machismo, an issue that has at times led to accusations of misogyny.

Hard rock or heavy rock is a heavier subgenre of rock music typified by aggressive vocals and distorted electric guitars. Hard rock began in the mid-1960s with the garage, psychedelic and blues rock movements. Some of the earliest hard rock music was produced by the Kinks, the Who, the Beatles, the Rolling Stones, Cream, Vanilla Fudge, and the Jimi Hendrix Experience. In the late 1960s, bands such as Blue Cheer, the Jeff Beck Group, Iron Butterfly, Led Zeppelin, Creedence Clearwater Revival, Golden Earring, Steppenwolf, Grand Funk Railroad, Free, and Deep Purple also produced hard rock.

The genre developed into a major form of popular music in the 1970s, with the Who, Led Zeppelin and Deep Purple being joined by Black Sabbath, Alice Cooper, Aerosmith, Kiss, Queen, AC/DC, Thin Lizzy and Van Halen. During the 1980s, some hard rock bands moved away from their hard rock roots and more towards pop rock. Established bands made a comeback in the mid-1980s and hard rock reached a commercial peak in the 1980s with glam metal bands such as Mötley Crüe, Bon Jovi and Def Leppard as well as the rawer sounds of Guns N' Roses which followed with great success in the later part of that decade.

Deep Purple are an English rock band formed in London in 1968. They are considered to be among the pioneers of heavy metal and modern hard rock, although their musical style has varied throughout their career. Originally formed as a psychedelic rock and progressive rock band, they shifted to a heavier sound with their 1970 album Deep Purple in Rock. Deep Purple have been referred to as being part of the "unholy trinity of British hard rock and heavy metal in the early to mid-'70s", alongside Led Zeppelin and Black Sabbath. Listed in the 1975 Guinness Book of World Records as "the globe's loudest band" for a 1972 concert at London's Rainbow Theatre, they have sold over 100 million records worldwide. Deep Purple have also generated several successful spinoff bands, including Rainbow, Whitesnake, and Gillan.

Deep Purple were founded by vocalist Rod Evans, guitarist Ritchie Blackmore, bassist Nick Simper, keyboardist Jon Lord and drummer Ian Paice. After three studio albums, the "Mark I" line-up came to an end in 1969 when Evans and Simper were dismissed from the band and replaced by Ian Gillan and Roger Glover respectively, forming the classic "Mark II" line-up of Deep Purple. Following the orchestral collaboration Concerto for Group and Orchestra (1969), the Mark II line-up recorded four studio albums – Deep Purple in Rock (1970), Fireball (1971), Machine Head (1972), and Who Do We Think We Are (1973) – and a live album – Made in Japan (1972) – that cemented their popularity and played a key role in shaping the emerging genres of hard rock and heavy metal. Gillan and Glover both left the band in 1973 and were replaced by David Coverdale and Glenn Hughes respectively. The "Mark III" line-up recorded two studio albums – Burn and Stormbringer (both 1974) – before Blackmore parted ways with the band in 1975 due to musical differences. He was replaced by Tommy Bolin, though after just one studio album with the "Mark IV" line-up – Come Taste the Band (1975) – Deep Purple disbanded in July 1976 and Bolin died from a drug overdose five months later.