Editing Hard rock (section)

==Definitions==
[[File:Backbeat chop.png|thumb|left|300px|Drum notation for a [[backbeat]]<ref>D. Anger, "Introduction to the '[[Backbeat chop|Chop]]'", ''Strad'' (0039–2049), 10 January 2006, vol. 117, issue 1398, pp. 72–7.</ref>]]
Hard rock is a form of loud, aggressive rock music. The electric guitar is often emphasised, used with [[Distortion (music)|distortion]] and other effects, both as a rhythm instrument using repetitive riffs with a varying degree of complexity, and as a solo [[Lead guitar|lead]] instrument.<ref name=AllMusicHard/> Drumming characteristically focuses on driving rhythms, strong bass drum and a [[beat (music)#Backbeat|backbeat]] on snare, sometimes using cymbals for emphasis.<ref name="Shuker2005">R. Shuker, ''Popular Music: the Key Concepts'', (Abingdon: Routledge, 2nd end., 2005), {{ISBN|0-415-34770-X}}, pp. 130–1.</ref> The bass guitar works in conjunction with the drums, occasionally playing riffs, but usually providing a backing for the rhythm and lead guitars.<ref name=Allmusicheavymetal/> Vocals are often growling, raspy, or involve screaming or wailing, sometimes in a high range, or even [[falsetto]] voice.<ref>E. Macan, ''Rocking the Classics: English Progressive Rock and the Counterculture'' (Oxford: Oxford University Press, 1997), {{ISBN|0-19-509887-0}}, p. 39.</ref>

In the late-1960s, the term [[heavy metal music|heavy metal]] was used interchangeably with hard rock, but gradually began to be used to describe music played with even more volume and intensity.<ref>P. Du Noyer, ed., ''The Illustrated Encyclopedia of Music'' (Flame Tree, 2003), {{ISBN|1-904041-70-1}}, p. 96.</ref> While hard rock maintained a bluesy [[rock and roll]] identity, including some [[swing (music)|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.<ref name="AllMusicHard">{{Citation |title=Hard Rock|work=Allmusic|url=https://www.allmusic.com/style/hard-rock-ma0000002636}}.</ref> 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.<ref name="Allmusicheavymetal">V. Bogdanov, C. Woodstra and S. T. Erlewine, ''All Music Guide to Rock: the Definitive Guide to Rock, Pop, and Soul'' (Milwaukee, WI: Backbeat Books, 3rd edn., 2002), {{ISBN|0-87930-653-X}}, pp. 1332–3.</ref> 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.<ref>R. Walser, ''Running With the Devil: Power, Gender, and Madness in Heavy Metal Music'' (Middletown, CT: Wesleyan University Press, 1993), {{ISBN|0-8195-6260-2}}, p. 7.</ref>