Hard rock (or heavy rock) is a loosely defined genre of rock music which has its earliest roots in mid-1960s garage rock, blues rock and psychedelic rock. It is typified by a heavy use of distorted electric guitars, bass guitar, drums, and often accompanied with pianos, and keyboards.
Hard rock developed into a major form of popular music in the 1970s, with bands like Led Zeppelin, Deep Purple, Aerosmith, AC/DC and Van Halen, and reached a commercial peak in the mid 1980s. The glam metal of bands like Bon Jovi and Def Leppard and the rawer sounds of Guns N' Roses followed up with great success in the later part of that decade, before losing popularity in the face of grunge. Despite this, many post-grunge bands adopted a hard rock sound and in the 2000s there came a renewed interest in established bands, attempts at a revival, and new hard rock bands that emerged from the garage rock and post punk revival.
Hard rock is a form of loud, aggressive rock music. The electric guitar is often emphasised, used with distortion and other effects, both as a rhythm instrument using simple repetitive riffs, and as a solo lead instrument. Drumming characteristically focuses on driving rhythms, strong bass drum and a backbeat on snare, sometimes using cymbals for emphasis. The bass guitar works in conjunction with the drums, occasionally playing riffs, but usually providing a backing for the rhythm and lead guitars. Vocals are often growling, raspy, or involve screaming or wailing, sometimes in a high range, or even falsetto voice. Hard rock has sometimes been labelled cock rock for its emphasis on overt masculinity and sexuality and because it has historically been predominately performed and consumed by men: in the case of its audience, particularly white, working-class adolescents.
In the late 1960s the term heavy metal was used interchangeably with hard rock, but gradually began to be used to describe music played with even more volume and intensity. While hard rock maintained a bluesy rock and roll identity, including some swing in the back beat and riffs that tended to outline chord progressions in their hooks, heavy metal's riffs often functioned as stand-alone melodies and had no swing in them. Heavy metal took on "darker" characteristics after Black Sabbath's breakthrough in the early 1970s and from the 1980s it developed a number of sub-genres, often termed extreme metal, which were influenced by hardcore punk, and which further differentiated the two styles. Despite this differentiation, hard rock and heavy metal have existed side by side, with bands frequently standing on the boundary of, or crossing between, the genres.
In the mid-1960s, American and in particular British rock bands began to modify rock and roll, adding to the standard genre greater blues influence, harder sounds, heavier guitar riffs, bombastic drumming and louder vocals. Early forms of hard rock can be heard in the Kingsmen's version of "Louie, Louie" (1963), which made it a garage rock standard, and the songs of British Invasion acts, including "You Really Got Me" by The Kinks (1964), "My Generation" by The Who (1965) and "(I Can't Get No) Satisfaction" (1965) by the Rolling Stones. From the late 1960s it became common to divide mainstream rock music that emerged from psychedelia into soft and hard rock. Soft rock was often derived from folk rock, using acoustic instruments and putting more emphasis on melody and harmonies. In contrast, hard rock was most often derived from blues-rock and was played louder and with more intensity.
Blues-rock acts that pioneered the sound included Cream, Jimi Hendrix Experience and The Jeff Beck Group. Cream, in songs like "I Feel Free" (1966) combined blues-rock with pop and psychedelia, particularly in the riffs and guitar solos of Eric Clapton. Jimi Hendrix produced a form of blues-influenced psychedelic rock, which combined elements of jazz, blues and rock and roll. From 1967 Jeff Beck brought lead guitar to new heights of technical virtuosity and moved blues-rock in the direction of heavy rock with his band, The Jeff Beck Group. Dave Davies of the Kinks, Keith Richards of the Rolling Stones, Pete Townshend of The Who, Hendrix, Clapton and Beck all pioneered the use of new guitar effects like phasing, feedback and distortion. Even The Beatles attempted to produce songs in the new hard rock style, trying to create a greater level of noise than The Who, from The Beatles (1968) (known as the White Album) onwards, beginning with "Helter Skelter". Some critics have written about its "proto-metal roar", but others have argued that "their attempts at the heavy style were without exception embarrassing".
Groups that emerged from the American psychedelic scene about the same time included Iron Butterfly, MC5, Blue Cheer and Vanilla Fudge. The San Francisco band Blue Cheer released a crude and distorted cover of Eddie Cochran's classic "Summertime Blues", from their debut album Vincebus Eruptum (1968), that outlined much of the later hard rock and heavy metal sound. The same month, Steppenwolf released its self-titled debut album (1968), including "Born to Be Wild", which contained the first lyrical reference to heavy metal and helped popularise the style when it was used in the film Easy Rider (1969). Iron Butterfly's In-A-Gadda-Da-Vida (1968), with its 17-minute-long title track, using organs and with a lengthy drum solo, also prefigured later elements of the sound.
At the end of the decade a distinct genre of hard rock was emerging with bands like Led Zeppelin, who mixed the music of early rock bands with a more hard-edged form of blues rock and acid rock on their first two albums Led Zeppelin (1969) and Led Zeppelin II (1969), and Deep Purple, who achieved their commercial breakthrough with their fourth and distinctively heavier album, In Rock (1970). Also significant was Black Sabbath's Paranoid (1970), which combined guitar riffs with dissonance and more explicit references to the occult and elements of Gothic horror. All three of these bands have been seen as pivotal in the development of heavy metal, but where metal further accentuated the intensity of the music, with bands like Judas Priest following Sabbath's lead into territory that was often "darker and more menacing", hard rock tended to continue to remain the more exuberant, good-time music.
In the early 1970s the Rolling Stones developed their hard rock sound with Exile on Main St. (1972). Initially receiving mixed reviews, according to critic Steve Erlewine it is now "generally regarded as the Rolling Stones' finest album". They continued to pursue the riff-heavy sound on albums including It's Only Rock 'n' Roll (1974) and Black and Blue (1976). Led Zeppelin began to mix elements of world and folk music into their hard rock from Led Zeppelin III (1970) and Led Zeppelin IV (1971). The latter included the track "Stairway to Heaven", which would become the most played song in the history of album-oriented radio. Deep Purple continued to define hard rock, particularly with their album Machine Head (1972), which included the tracks "Highway Star" and "Smoke on the Water". In 1975 guitarist Ritchie Blackmore left, going on to form Rainbow and after the break-up of the band the next year, vocalist David Coverdale formed Whitesnake. 1970 saw The Who release Live at Leeds, often seen as the archetypal hard rock live album, and the following year they released their highly-acclaimed album Who's Next, which mixed heavy rock with extensive use of synthesizers. Subsequent albums, including Quadrophenia (1973), built on this sound before Who Are You (1978), their last album before the death of pioneering rock drummer Keith Moon later that year.
Emerging British acts included Free, who released their signature song "All Right Now" (1970), which has received extensive radio airplay in both the UK and US. After the breakup of the band in 1973, vocalist Paul Rodgers joined supergroup Bad Company, whose eponymous first album (1974) was an international hit. Scottish band Nazareth released their self-titled début album in 1970, producing a blend of hard rock and pop that would culminate in their best selling, Hair of the Dog (1975), which contained the proto-power ballad "Love Hurts". The mixture of hard rock and progressive rock, evident in the works of Led Zeppelin and Deep Purple, was pursued more directly by bands like Uriah Heep and Argent. Having enjoyed some national success in the early 1970s, Queen, after the release of Sheer Heart Attack (1974) and A Night at the Opera (1975), gained international recognition with a sound that used layered vocals and guitars and mixed hard rock with glam rock, heavy metal, progressive rock, and even opera. The latter featured the single "Bohemian Rhapsody", which stayed at number 1 in the UK charts for nine weeks.
In the United States, macabre-rock pioneer Alice Cooper achieved mainstream success with the top ten album School's Out (1972). In the following year blues rockers ZZ Top released their classic album Tres Hombres and Aerosmith produced their eponymous début, as did Southern rockers Lynyrd Skynyrd and proto-punk outfit New York Dolls, demonstrating the diverse directions being pursued in the genre. Montrose, including the instrumental talent of Ronnie Montrose and vocals of Sammy Hagar and arguably the first all American hard rock band to challenge the British dominance of the genre, released their first album in 1973. Kiss built on the theatrics of Alice Cooper and the look of the New York Dolls to produce a unique band persona, achieving their commercial breakthrough with the double live album Alive! in 1975 and helping to take hard rock into the stadium rock era. In the mid-1970s Aerosmith achieved their commercial and artistic breakthrough with Toys in the Attic (1975), which reached number 11 in the American album chart and Rocks (1976) which peaked at number 3. Blue Öyster Cult, formed in the late 60s, picked up on some of the elements introduced by Black Sabbath with their breakthrough live gold album On Your Feet or on Your Knees (1975), followed by their first platinum album, Agents of Fortune (1976), containing the hit single "(Don't Fear) The Reaper", which reached number 12 on the Billboard charts. Journey released their eponymous debut in 1975 and the next year Boston released their highly successful début album. In the same year, hard rock bands featuring women saw commercial success as Heart released Dreamboat Annie and The Runaways débuted with their self-titled album. While Heart had a more folk-oriented hard rock sound, the Runaways leaned more towards a mix of punk-influenced music and hard rock. The Amboy Dukes, having emerged from the Detroit garage rock scene and most famous for their Top 20 psychedelic hit "Journey to the Centre of the Mind" (1968), were dissolved by their guitarist Ted Nugent, who embarked on a solo career that resulted in four successive multi-platinum albums between Ted Nugent (1975) and his best selling Double Live Gonzo (1978).
From outside of Britain and the United States, the Canadian trio Rush released three distinctively hard rock albums in 1974–75 (Rush, Fly by Night, and Caress of Steel) before moving toward a more progressive sound. The Irish band Thin Lizzy, which had formed in the late 1960s, made their most substantial commercial breakthrough in 1976 with the hard rock album Jailbreak and their worldwide hit "The Boys Are Back in Town" which reached number 8 in the UK, and number 12 in the US. Their style, consisting of two duelling guitarists often playing leads in harmony, proved itself to be a large influence on later bands. They reached their commercial, and arguably their artistic peak with Black Rose: A Rock Legend (1979). The arrival of Scorpions from Germany marked the geographical expansion of the sub-genre. Australian-formed AC/DC, with a stripped back, riff heavy and abrasive style that also appealed to the punk generation, began to gain international attention from 1976, culminating in the release of their multi-platinum albums Let There Be Rock (1977) and Highway to Hell (1979). Also influenced by a punk ethos were heavy metal bands like Motörhead, while Judas Priest abandoned the remaining elements of the blues in their music, further differentiating the hard rock and heavy metal styles and helping to create the New Wave of British Heavy Metal which was pursued by bands like Iron Maiden, Saxon and Venom.
With the rise of disco in the U.S. and punk rock in the UK, hard rock's mainstream dominance was rivalled toward the later part of the decade. Disco appealed to a more diverse group of people and punk seemed to take over the rebellious role that hard rock once held. Early punk bands like The Ramones explicitly rebelled against the drum solos and extended guitar solos that characterised stadium rock, with almost all of their songs clocking in around two minutes with no guitar solos. However, new rock acts continued to emerge and record sales remained high into the 1980s. 1977 saw the début and rise to stardom of Foreigner, who went on to release several platinum albums through to the mid 1980's. Midwestern groups like Kansas, REO Speedwagon and Styx helped further cement heavy rock in the Midwest as a form of stadium rock. In 1978, Van Halen emerged from the Los Angeles music scene with a sound based around the skills of lead guitarist Eddie Van Halen. He popularised a guitar‐playing technique of two‐handed hammer‐ons and pull‐offs called tapping, showcased on the song "Eruption" from the album Van Halen, which was highly influential in re‐establishing hard rock as a popular genre after the punk and disco explosion, while also redefining and elevating the role of electric guitar.