Hard rock

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.

Hard rock began losing popularity with the commercial success of R&B, hip-hop, urban pop, grunge and later Britpop in the 1990s. Despite this, many post-grunge bands adopted a hard rock sound and the 2000s saw a renewed interest in established bands, attempts at a revival, and new hard rock bands. In the 2000s, only a few hard rock bands from the 1970s and 1980s managed to sustain highly successful recording careers.

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 repetitive riffs with a varying degree of complexity, 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.

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. In the 1980s, heavy metal developed a number of subgenres, often termed extreme metal, some of which were influenced by hardcore punk, and which further differentiated the two styles. Despite this differentiation, hard rock and heavy metal have coexisted with one another, with bands frequently flirting with the boundaries of, or hybridizing the genres.

The roots of hard rock can be traced back to the mid-to-late 1950s, particularly electric blues, which laid the foundations for key elements such as a rough declamatory vocal style, heavy guitar riffs, string-bending blues-scale guitar solos, strong beat, thick riff-laden texture, and posturing performances. Electric blues guitarists began experimenting with hard rock elements such as driving rhythms, distorted guitar solos and power chords in the 1950s, evident in the work of Memphis blues guitarists such as Joe Hill Louis, Willie Johnson, and particularly Pat Hare, who captured a "grittier, nastier, more ferocious electric guitar sound" on records such as James Cotton's "Cotton Crop Blues" (1954). Other antecedents include Link Wray's instrumental "Rumble" in 1958, and the surf rock instrumentals of Dick Dale, such as "Let's Go Trippin'" (1961) and "Misirlou" (1962).

In the 1960s, American and British blues and rock bands began to modify rock and roll by adding harder sounds, heavier guitar riffs, bombastic drumming, and louder vocals, from electric blues. Early forms of hard rock can be heard in the work of Chicago blues musicians Elmore James, Muddy Waters, and Howlin' Wolf, the Kingsmen's version of "Louie Louie" (1963) which made it a garage rock standard, and songs of R&B-influenced British Invasion acts, such as "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. 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, the 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. Cream's best known-song, "Sunshine of Your Love" (1967), is sometimes considered to be the culmination of the British adaptation of blues into rock and a direct precursor of Led Zeppelin's style of hard rock and heavy metal. 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. The Doors' debut album, released in 1967, included songs like "Soul Kitchen", "Twentieth Century Fox", and a cover version of "Back Door Man", which were what music journalist Stephen Davis characterized as "enough hard rock tracks". One track that stands out as especially heavy for its time is the last 1:10 of "I Feel Much Better" by the Small Faces, recorded in May 1967. The first 2:46 is typical psychedelic fare of the time, but then the song suddenly changes into a hard bass-and-guitar power chord with Steve Marriott's rhythm guitar and gut bucket singing, equal to the heaviest rock to be heard later. The Beatles began producing songs in the new hard rock style beginning with their 1968 double album The Beatles (also known as the "White Album") and, with the track "Helter Skelter", attempted to create a greater level of noise than the Who. Stephen Thomas Erlewine of AllMusic has referred to the "proto-metal roar" of "Helter Skelter", while Ian MacDonald called it "ridiculous, with McCartney shrieking weedily against a massively tape-echoed backdrop of out-of-tune thrashing".