View source for Acid rock

{{short description|Subgenre of psychedelic rock music}}
{{Redirect|Heavy psych|the album|Heavy Psych}}
{{Distinguish|Acidic rock}}

{{Infobox music genre
| name              = Acid rock
| stylistic_origins = {{flatlist|
* [[Rock music|Rock]]{{sfn|Browne|Browne|2001|p=8}}
* [[psychedelic music|psychedelia]]{{sfn|Hull|2003|p=380}}
* [[garage rock]]{{sfn|Hoffmann|2004|p=1725}}
* [[hard rock]]{{sfn|Hoffmann|2004|p=1725}}{{efn|name=s}}
* [[blues]]{{sfn|Knowles|2010|p=199}}
* [[folk rock]]{{sfn|Jasinski|2012}}
* [[psychedelic rock]]{{sfn|Drabløs|2016|p=64}}{{sfn|Freeman|Freeman|1996|p=10}}{{efn|"Psychedelic rock" may also be a synonym.<ref name="syn"/>}}
}}
| cultural_origins  = Mid-1960s, United States
| derivatives       = * [[Hard rock]]{{sfn|Bill|1984|p=37}}{{efn|name=s|Either an influence or derivative according to the sources.}}
* [[krautrock]]<ref name="Reynolds1996">{{cite magazine|title= Krautrock|first= Simon|last= Reynolds|magazine= Melody Maker|date= July 1996|author-link= Simon Reynolds}}</ref>
* [[Heavy metal music|heavy metal]]<ref name="loyola">{{cite journal|title=Loyola Entertainment Law Journal|journal=Loyola Entertainment Law Journal|date=1986|volume=6|page=90|url=https://books.google.com/books?id=eRdMAQAAIAAJ&q=+%22acid+rock%22}}</ref>
* [[progressive rock]]{{sfn|Holm-Hudson|2013|p=85}}
| fusiongenres      = * [[Stoner metal]]<ref name=AMStonerrock>{{AllMusic|class=style|id=stoner-metal-ma0000011961|label=Stoner Metal}}.</ref>

| local_scenes      = [[San Francisco Sound]]
| other_topics      = * [[List of acid rock artists|List of artists]]
* [[acid punk]]
* [[proto-metal]]
| footnotes         = {{notelist}}
}}
{{Psychedelic sidebar}}

'''Acid rock''' is a loosely defined type of [[rock music]]{{sfn|Browne|Browne|2001|p=8}} that evolved out of the mid-1960s [[garage rock|garage <!----The source in the article says "garage punk", which is a valid term for the 1960s genre. If you want to change this to "rock", you will have to provide a reliable source.--->punk]]{{sfn|Hoffmann|2004|p=1725}} movement and helped launch the [[psychedelia|psychedelic subculture]]. While the term has sometimes been used interchangeably with "[[psychedelic rock]]", acid rock also specifically refers to a more musically intense, rawer, or heavier subgenre or sibling of psychedelic rock. Named after [[lysergic acid diethylamide]] (LSD), the style is generally defined by heavy, [[Distortion (music)|distorted]] guitars and often contains lyrics with drug references and long improvised [[Jam session|jams]].  

Compared to other forms of psychedelic rock, acid rock features a harder, louder, heavier, or rawer sound. Much of the style overlaps with [[Garage rock|1960s garage punk]], [[proto-metal]], and early heavy, [[blues]]-based [[hard rock]]. It developed mainly from the [[American West Coast]], where groups did not focus on the novelty recording effects or whimsy of British psychedelia; instead, the subgenre emphasized the heavier qualities associated with both the positive and negative extremes of the [[psychedelic experience]].

As the movement progressed into the late 1960s and 1970s, elements of acid rock split into two directions, with hard rock and [[heavy metal music|heavy metal]] on one side and [[progressive rock]] on the other. In the 1990s, the [[stoner metal]] genre combined acid rock with other hard rock styles such as [[grunge]] and [[doom metal]], updating the heavy riffs and long jams found in acid rock and psychedelic-influenced metal.

==Definitions==
{{See also|Psychedelic music|Psychedelic rock}}
"Acid rock" as a term was initially (and often still is) loosely defined.{{sfn|Gammond|1991|p=3}} In 1969, as the genre was still solidifying, rock journalist [[Nik Cohn]] called it a "fairly meaningless phrase that got applied to any group, no matter what its style".{{sfn|Hull|2003|p=380}} The term was originally used to describe the background music for [[acid trip]]s in underground parties in the 1960s (e.g. the [[Merry Pranksters]]' "Acid Tests"){{sfn|Wolfe|1968|p=223}} and as a catchall term for the more eclectic [[Haight-Ashbury]] bands in [[San Francisco]].{{sfn|Knowles|2010|p=199}} The [[Grateful Dead]]'s [[Jerry Garcia]] believed that acid rock is music you listen to while under the influence of acid, further stating that there is no real "[[psychedelic rock]]" and that it is [[Indian classical music]] and some [[Music of Tibet#Chanting|Tibetan music]] "designed to expand consciousness".{{sfn|Rolling Stone Magazine Staff|1989|p=195}}

{{quote box
| quote = Psychedelia was sometimes referred to as "acid rock". The latter label was applied to a pounding, [[hard rock]] variant that evolved out of the mid-1960s [[garage-punk]] movement ... When rock began turning back to softer, roots-oriented sounds in late 1968, acid-rock bands mutated into [[heavy metal music|heavy metal]] acts.
| source = —Frank Hoffman, ''Encyclopedia of Recorded Sound'' (2004){{sfn|Hoffmann|2004|p=1725}}
| align = left
| width = 25%
}}

The term has often been deployed interchangeably with "psychedelic rock" or "psychedelia", particularly during the genre's nascence.<ref name="syn">{{harvnb|Hoffmann|2004|p=1725|loc="Psychedelia was sometimes referred to as 'acid rock.'"}}; {{harvnb|Browne|Browne|2001|p=8|loc="acid rock, also known as psychedelic rock"}}; {{harvnb|DeRogatis|2003|p=9|loc="now regularly called 'psychedelic' or 'acid'-rock"}}; {{harvnb|Larson|2004|p=140|loc="known as acid rock or psychedelic rock"}}</ref> However, the distinction between the heavier "acid rock" and the more general or inclusive genre of "psychedelic rock" has been well established.<ref name=AMgenre/>  According to Per Elias Drabløs, "acid rock is generally considered a subgenre of psychedelic rock",{{sfn|Drabløs|2016|p=64}} while Steve and Alan Freeman state the two terms are more or less synonymous, and that "what is usually referred to as acid rock is generally the more extreme end of [the psychedelic rock genre]".{{sfn|Freeman|Freeman|1996|p=10}} This would mean psychedelic rock that is heavier, louder, or harder.<ref name=AMgenre>{{AllMusic|class=style|id=acid-rock-ma0000012327}}</ref>{{sfn|McLauchlin|2015|p={{page needed|date=June 2016}}}}{{sfn|Jasinski|2012}} Additionally, music critics later retroactively labelled the bridge between acid rock and later hard rock and heavy metal acts as "heavy psych".<ref>{{Cite web |last=Terich |first=Jeff |date=2013-04-25 |title=10 Essential Heavy Psych Albums |url=https://www.treblezine.com/10-essential-heavy-psych-albums/ |access-date=2024-06-15 |website=Treble |language=en-US}}</ref>

When defined specifically as a [[hard rock]] variant of psychedelia, acid rock is distinguished as having evolved from the 1960s [[garage punk]] movement, with many of its bands eventually transforming into [[heavy metal music|heavy metal]] acts.{{sfn|Hoffmann|2004|p=1725}}{{refn|group=nb|Exemplary acts of "garagey" psychedelia include [[Blues Magoos]], [[the Electric Prunes]], and [[the Music Machine]], all of which may fall under the label of acid rock.{{sfn|Bisbort|Puterbaugh|2000|p=31}}}} Percussionist John Beck defines "acid rock" as synonymous with [[hard rock]] and [[heavy metal music|heavy metal]].{{sfn|Beck|2013|p=335}}{{refn|group=nb|Hard rock and heavy metal have been described by writer Steve Valdez as evolving from psychedelic rock.{{sfn|Henderson|Stacey|2014|p=539}}}} The term eventually encompassed heavy, [[blues]]-based hard rock bands.{{sfn|Knowles|2010|p=199}} Musicologist Steve Waksman wrote that "the distinction between acid rock, hard rock, and heavy metal can at some point never be more than tenuous".{{sfn|Waksman|2001|p=262}} {{clear left}}

==Origins and ideology==
{{Further|Psychedelia|Counterculture of the 1960s}}
[[File:A female demonstrator offers a flower to military police on guard at the Pentagon during an anti-Vietnam demonstration. Arlington, Virginia, USA.jpg|thumb|left|upright=0.9|A group of [[Flower Power]] demonstrators, 1967]]

Many bands associated with acid rock aimed to create a youth movement based on love and peace, as an alternative to [[workaholic]] [[capitalist]] society.{{sfn|Szatmary|2014|pp={{page needed|date=April 2016}}}} David P. Szatmary states, "a legion of rock bands, playing what became known as 'acid rock,' stood in the vanguard of the movement for cultural change."{{sfn|Szatmary|2014|p=158}} Szatmary also quotes from the ''[[San Francisco Oracle]]'', an underground newspaper published between 1966 and 1968, to explain how rock music was perceived at that time and how the acid rock movement emerged: "Rock music is a regenerative and [[revolution]]ary art, offering us our first real hope for the future (indeed, for the present)."{{sfn|Szatmary|2014|p=158}}

When played live at dance clubs, performances were accompanied by [[liquid light show|psychedelic-themed light shows]]{{sfn|Misiroglu|2015|p=10}} in order to replicate the visual effects of the acid experience.{{sfn|McEneaney|2009|p=45}} According to Kevin T. McEneaney, the [[Grateful Dead]] "invented" acid rock in front of a crowd of concertgoers in [[San Jose, California]] on December 4, 1965, the date of the second [[Acid Tests|Acid Test]] held by author [[Ken Kesey]]. Their stage performance involved the use of [[strobe light]]s to reproduce LSD's "surrealistic fragmenting" or "vivid isolating of caught moments".{{sfn|McEneaney|2009|p=45}} The Acid Test experiments subsequently launched the psychedelic subculture.{{sfn|McEneaney|2009|p=46}} Author [[Steve Turner (writer)|Steve Turner]] recognises [[the Beatles]]' success in conveying an LSD-inspired worldview on their 1966 album ''[[Revolver (Beatles album)|Revolver]]'', especially with the track "[[Tomorrow Never Knows]]", as having "opened the doors" to acid rock.<ref>{{cite book|last=Turner|first=Steve|title=Beatles '66: The Revolutionary Year|year=2016|publisher=HarperLuxe|location=New York, NY|isbn=978-0-06-249713-0|page=626}}</ref>{{refn|group=nb|''[[Rolling Stone]]'' attributes the development of the Los Angeles and San Francisco music scenes, including subsequent releases by [[the Beach Boys]], [[Love (band)|Love]] and the Grateful Dead, to the influence of ''Revolver'', particularly the song "[[She Said She Said]]".<ref>{{cite web|url=https://www.rollingstone.com/music/lists/100-greatest-beatles-songs-20110919/she-said-she-said-19691231 |title=100 Greatest Beatles Songs: 37. 'She Said, She Said'|publisher=[[Rolling Stone|rollingstone.com]]|date=19 September 2011|access-date=16 December 2016}}</ref>}} Former [[Atlantic Records]] executive Phillip Rauls recalls: "I was in the music business at the time, and my very first recognition of acid rock ... was, of all people, [[the Beach Boys]] and the song '[[Good Vibrations]]' ... That [song's electro [[theremin]]] sent so many musicians back to the studio to create this music on acid."{{sfn|Romano|2010|pp=17–18}}{{refn|group=nb|Rauls believed that, at the time, "acid rock" was used to refer to "progressive rock".{{sfn|Romano|2010|pp=17–18}} Writer Vernon Joyson observed flirtations with acid rock in the Beach Boys' albums ''[[Pet Sounds]]'' (1966) and the unfinished ''[[Smile (The Beach Boys album)|Smile]]''.{{sfn|Joyson|1984|p=8}}}}

[[File:Jefferson Airplane early 1966.jpg|thumb|right|[[Jefferson Airplane]], early 1966]]

According to Laura Diane Kuhn, the heavier form of psychedelic rock known as acid rock developed from the late 1960s [[California]] music scene.{{sfn|Kuhn|1999|p=1507}} [[The Charlatans (American band)|The Charlatans]] were among the first [[Bay Area]] acid rock bands. [[Jefferson Airplane]] was the first Bay Area acid rock band to sign a major label and achieve mainstream success.{{sfn|Larson|2004|p=141–144}} By July 1967, ''[[Time (magazine)|Time]]'' magazine wrote, "From [[jukebox]]es and [[transistor radio|transistors]] across the nation pulses the turned-on sound of acid-rock groups: the Jefferson Airplane, [[the Doors]], [[Moby Grape]]".<ref>{{cite magazine |url=http://www.time.com/time/magazine/article/0,9171,899555-2,00.html |archive-url=https://web.archive.org/web/20080203145742/http://www.time.com/time/magazine/article/0,9171,899555-2,00.html |url-status=dead |archive-date=February 3, 2008 |title=Youth: The Hippies |magazine=[[Time (magazine)|Time]] |issue=July 7, 1967}}{{subscription required}}</ref> In 1968, ''[[Life (magazine)|Life]]'' magazine referred to the Doors as the "kings of acid rock".<ref>{{cite magazine |last=Powledge |first=Fred |title=Wicked Go The Doors |magazine=[[Life (magazine)|Life]] |issue=April 12, 1968}}</ref>{{refn|group=nb|Joyson notes that the Doors' acid rock music was markedly different from their San Francisco contemporaries; that the Doors "took the acid experience less literally".{{sfn|Joyson|1984|p=59}}}}

Other bands credited with creating or laying the foundation for acid rock include [[garage rock]] bands such as [[the 13th Floor Elevators]] and [[Count Five]].{{sfn|Browne|Browne|2001|p=8}}{{sfn|Moore|2015|p=126}} The [[blues rock]] group the [[Paul Butterfield Blues Band]] are also credited with spawning the harder acid rock sound,<ref name="northjersey">{{cite web|last1=Roberts|first1=Randall|title=Laying the odds on the Rock Hall of Fame nominees|url=http://www.northjersey.com/arts-and-entertainment/music/laying-the-odds-on-the-rock-hall-of-fame-nominees-1.635201?page=all|website=NorthJersey.com|access-date=1 May 2016}}</ref> and their 1966 instrumental "[[East-West (instrumental)|East-West]]", with its early use of the extended [[guitar solo|rock solo]], has been described as laying "the roots of psychedelic acid rock"<ref name="paulbutterfield">{{cite web|last1=Erlewine|first1=Michael|title=East-West Live - The Paul Butterfield Band|url=http://www.allmusic.com/album/east-west-live-mw0000184524|website=AllMusic|access-date=1 May 2016}}</ref> and featuring "much of acid-rock's eventual DNA".<ref name="ultimateclassic">{{cite web|last1=Giles|first1=Jeff|title=How the Paul Butterfield Blues Band Earned Its Spot in the Rock and Roll Hall of Fame|url=http://ultimateclassicrock.com/paul-butterfield-rock-and-roll-hall-of-fame/|website=Ultimate Classic Rock|date=16 December 2014 |access-date=1 May 2016}}</ref> The Beatles' June 1967 album ''[[Sgt. Pepper's Lonely Hearts Club Band]]'' was a major influence on American acid rock groups.{{sfn|Browne|Browne|2001|p=8}}

==Development and characteristics==

=== Garage-psych ===
{{See also|Garage rock|Proto-punk}}

Originating in the early 1960s, [[garage rock]] was a mainly-American movement that involved [[Rhythm and blues|R&B]]-inspired [[garage band]]s powered by electric guitars and organs.<ref name="Hann (Garage Punk)"/> It was mainly the domain of untrained teenagers fixated on sonic effects, such as [[wah-wah (music)|wah-wah]] and fuzz tone, and relied heavily on [[riff]]s.{{sfn|Reynolds|2012|p=150}} The music later blurred into psychedelia.<ref name="Hann (Garage Punk)">{{cite web|url=https://www.theguardian.com/music/musicblog/2014/jul/30/10-of-the-best-garage-punk|title=10 of the best: garage punk|last=Hann|first=Michael|date=July 30, 2014|website=[[The Guardian]]|access-date=June 18, 2016}}</ref> American garage bands retained the rawness and energy of garage rock, while incorporating its use of heavy distortion, feedback, and layered sonic effects into their versions of psychedelic music, which spawned early examples of "acid rock".<ref name=garage>{{AllMusic|class=style|id=psychedelic-garage-ma0000002800|label=Psychedelic/Garage}}.</ref> Bisport and Puterbaugh, who defined acid rock as an intense or raw form of psychedelia, include "garagey" psychedelia under the label of "acid rock" due in part to its "energy and intimation of psychic overload".{{sfn|Bisbort|Puterbaugh|2000|p=31}} Exemplary garage-psych acts include [[Blues Magoos]], [[the Electric Prunes]], and [[the Music Machine]].{{sfn|Bisbort|Puterbaugh|2000|p=31}}

{{listen|pos=right
|filename=Psychotic Reaction - Count Five.ogg|title=Count Five – "Psychotic Reaction" (1966)
|description=[[Count Five]]'s "[[Psychotic Reaction]]", among the first successful acid (or psychedelic) rock songs, contained the characteristics that would come to define acid rock: the use of feedback and distortion replacing early rock music's more melodic electric guitars.{{sfn|Browne|Browne|2001|p=8}} }}

The earliest known use of the terms "[[garage punk]]" or "garage rock" appeared in [[Lenny Kaye]]'s track-by-track [[liner notes]] for the 1972 anthology compilation ''[[Nuggets: Original Artyfacts from the First Psychedelic Era, 1965-1968]]'', to describe a song by [[the Shadows of Knight]], as "classic garage punk". At the time, the term "[[punk rock]]" referred to the garage rock of the 1960s, with the compilation's liner notes containing one of the earliest known uses of the term.<ref name="austen">{{cite book |last1=Austen |first1=Jake |url=https://books.google.com/books?id=GYa5olqdl4UC&q=1960s+punk+rock+garage&pg=PA168 |title=TV-a-Go-Go |date=2005 |publisher=Chicago Review Press |isbn=978-1-56976-241-7}}</ref><ref name="billboard">{{cite magazine |last1=Shaw |first1=Greg |date=Jan 14, 1978 |title=New Trends of the New Wave |url=https://books.google.com/books?id=piQEAAAAMBAJ&q=%22acid+rock%22+%22nuggets%22&pg=PT59 |access-date=23 November 2015 |magazine=Billboard}}</ref>{{sfn|Nobles|2012|p=32}} Musicologist [[Simon Frith]] cites ''Nuggets'', as a showcase for the garage psychedelia of the 1960s, with the compilation epitomizing an overlap between 1960s garage rock and early psychedelia.{{sfn|Eder|2001|p=95}}{{sfn|Frith|2004|p=98}}{{sfn|Case|2010|p=265}} Bands such as the [[Count Five]], with their 1966 single "[[Psychotic Reaction]]", contained some of the earliest characteristics that would later come to define acid rock, such as the emphasizing of guitar feedback and distortion over traditional rock instrumentation.{{sfn|Browne|Browne|2001|p=8}}

Another group included on the ''Nuggets'' album, the 13th Floor Elevators from Austin, Texas, began as a straight garage rock band before becoming one of the original early acid rock bands and pioneers of psychedelic rock in general, with a sound consisting of guitar effects, screeching vocals, and "occasionally demented" lyrics.{{sfn|Unterberger|2002|p=1135}}  Their debut album, ''[[The Psychedelic Sounds of the 13th Floor Elevators]]'', featuring the garage rock hit "[[You're Gonna Miss Me (song)|You're Gonna Miss Me]]", was among the earliest psychedelic rock albums.<ref name=miss>{{cite web|url=http://www.allmusic.com/song/youre-gonna-miss-me-mt0011386883|title=You're Gonna Miss Me - Song review|work=allmusic.com|author=Unterberger, Richie}}</ref>{{sfn|Unterberger|2002|p=1135}} At around the same time, New York City's the Blues Magoos were referring to their wailing garage and blues rock as "psychedelic music", which would also be increasingly labeled "acid rock".{{sfn|Hoffmann|2004|p=1725}}

===Distinctions from other psychedelic rock===
{{Main|Psychedelic rock}}

[[File:Jimi Hendrix 1967 uncropped.jpg|thumb|left|[[Jimi Hendrix]] performing in 1967]]

Acid rock often encompasses the more extreme side of the psychedelic rock genre, frequently containing a loud, improvised, and guitar-centered sound.{{sfn|Freeman|Freeman|1996|p=10}} Alan Bisbort and Parke Puterbaugh write that acid rock "can best be described as psychedelia at its rawest and most intense ... [[Bad trip]]s as well as good, riots as well as peace, pain as well as pleasure - the whole spectrum of reality, not just the idyllic bits, were captured by acid rock."{{sfn|Bisbort|Puterbaugh|2000|p=31}} "Acid rock" has also been described as more heavily electric and containing more [[distortion (music)|distortion]] ("fuzz") than typical psychedelic rock.{{sfn|Luft|2009|p=173}} By the late 1960s, in addition to the deliberate use of distortion and [[Audio feedback|feedback]], acid rock was further characterized by long [[guitar solo]]s and the frequent use of [[electronic organ]]s.{{sfn|Browne|Browne|2001|p=8}} Lyric references to [[Recreational drug use|drug use]] were also common, as exemplified in Jefferson Airplane's 1967 song "[[White Rabbit (Jefferson Airplane song)|White Rabbit]]" and [[Jimi Hendrix Experience]]'s 1967 song "[[Purple Haze]]".{{sfn|Browne|Browne|2001|p=8}} Lyrical references to drugs such as LSD were often cryptic.{{sfn|Kuhn|1999|p=1507}}

{{listen|pos=right
|filename=Sky Pilot Animals.ogg|title=The Animals – "Sky Pilot" (1968)
|description=Crossover in the two major psychedelic rock variants (acid rock and British-influenced psychedelic rock) did occur; [[the Animals]]' song "[[Sky Pilot (song)|Sky Pilot]]" was among the few songs of the era to juxtapose the elaborate orchestration of ''[[Sgt. Pepper's Lonely Hearts Club Band|Sgt. Pepper]]''-influenced, British-style psychedelic rock with the more Hendrix-influenced, electric guitar-centered American acid rock style.{{sfn|Perone|2001|p=56}}}}

At a time when many British psychedelic bands played whimsical or [[surrealist]]ic psychedelic rock, many 1960s American rock bands, especially those from the [[West Coast of the United States|West Coast]], developed a rawer or harder version of psychedelic rock containing garage rock energy.<ref name=garage/> When contrasted with whimsical British psychedelia, this harder American West Coast variant of psychedelic rock has been referred to as acid rock.{{sfn|Brend|2005|p=88}}{{refn|group=nb|British psychedelia was often more arty in its experimentation, and it tended to stick within pop song structures.<ref name=britpsych>{{AllMusic|class=style|id=british-psychedelia-ma0000012038|label=British Psychedelia}}</ref> Along with its whimsical and surrealist tendencies, British psychedelic rock was generally not as [[minimalist]] and not as aggressive as its American counterpart, often featuring longer song arrangements and incorporating [[Eastern world|Eastern]] instruments such as [[sitars]].<ref name="britannica">{{cite web|last1=O'Brien|first1=Lucy M.|title=Psychedelic Rock|url=https://www.britannica.com/art/psychedelic-rock|website=Encyclopædia Britannica|access-date=27 April 2016}}</ref>}} American psychedelic rock and [[garage band]]s such as the 13th Floor Elevators epitomized the frenetic, darker and more psychotic sound of American acid rock, a sound characterized by [[Drone (music)|droning]] guitar riffs, amplified feedback, and guitar distortion.<ref name="britannica"/> Hoffman writes that acid rock lacked the [[recording studio]] "gimmickry" that typified the more Beatles-influenced strain of psychedelic rock, though acid rock experimented in other ways with electrified guitar effects.{{sfn|Hoffmann|2004|p=1725}}

Tonal distortion was also one of the defining characteristics of the [[San Francisco Sound]].{{sfn|Dasher|1985|p=67}} The acid rock of the San Francisco Sound heavily incorporated [[musical improvisation]], [[jam session|jamming]], repetitive drum beats, experimental sound and tape effects, and intentional feedback.{{sfn|Misiroglu|2015|p=10}} [[San Francisco]] acid rock generally took a non-commercial approach to song-writing: it often involved almost [[free jazz]]-like, free-form hard rock improvisations alongside distorted guitars, and lyrics often were socially conscious, trippy, or [[anti-establishment]].{{sfn|Larson|2004|p=140–141}} Many of the musicians in the scene, including bands such as the Charlatans and the [[Quicksilver Messenger Service]], became involved in [[Ken Kesey]]'s LSD-driven psychedelic scene, known as the Merry Pranksters.{{sfn|Misiroglu|2015|p=10}}

===Transition to hard rock and heavy metal===
{{Main|Hard rock|Heavy metal music}}
{{See also|Stoner metal|Progressive rock}}

Heavy metal evolved from psychedelic music and acid rock{{sfn|Brown|1986|p=148}} and added psychedelic/acid rock to the basic structure of [[blues rock]].{{sfn|Weinstein|2009|p=19}} In the 1960s, the heavy, [[blues]]-influenced, psychedelic hard rock sound of bands such as the [[Jimi Hendrix Experience]], [[Deep Purple]], and [[Cream (band)|Cream]] was classified as acid rock.{{sfn|Knowles|2010|p=199}} Other acid rock groups such as [[Blue Cheer]], [[Iron Butterfly]], and [[Vanilla Fudge]] served as examples of early heavy metal, or [[proto-metal]], creating stripped-downed, loud, intense, and "[[Fuzztone|fuzzy]]" acid rock or hard rock.{{sfn|Knowles|2010|p=199}} Bands such as Blue Cheer, Cream, and the hard rock group [[The Amboy Dukes (band)|The Amboy Dukes]] have all been described as "leading practitioners" of the harder variant of psychedelic rock known as "acid rock".{{sfn|Hoffmann|2004|p=1725}} Many acid rock bands would subsequently become heavy metal bands.<ref name=AMgenre /> 

{{listen|pos=left
|filename=In-a-Gadda-Da-Vida sample.ogg|title=Iron Butterfly – "In-A-Gadda-Da-Vida" (1968)
|description=[[Iron Butterfly]]'s "[[In-A-Gadda-Da-Vida]]" is sometimes described as an example of the transition from acid rock into heavy metal,{{sfn|Rood|1994|p=6}} a movement that proved to be massively influenced by their [[In-A-Gadda-Da-Vida (album)|album of the same name]].{{sfn|Bukszpan|Dio|2003|p=288}}}}

The influence of acid rock was evident in the sound of heavy metal in the 1970s.{{sfn|Rood|1994|p=6}} Iron Butterfly's "[[In-A-Gadda-Da-Vida]]" is sometimes described as an example of the transition between acid rock and heavy metal{{sfn|Rood|1994|p=6}} or the turning point in which acid rock became "heavy metal".<ref name="houstonpress">{{cite web|last1=Smith|first1=Nathan|title=The Warning: The 10 Heaviest Albums Before Black Sabbath|url=http://www.houstonpress.com/music/the-warning-the-10-heaviest-albums-before-black-sabbath-6779079|website=Houston Press|access-date=26 April 2016}}</ref> "In-A-Gadda-Da-Vida" serves a notable example of 1960s and early 1970s acid rock or heavy psychedelia, and the band would continue to experiment with distorted, "fuzzy", heavy psychedelia into the 1970s.{{sfn|Unterberger|2002|p=563}} Both Iron Butterfly's 1968 album [[In-A-Gadda-Da-Vida (album)|''In-A-Gadda-Da-Vida'']] and Blue Cheer's 1968 album ''[[Vincebus Eruptum]]'' have been described as influential in the transition of acid rock into heavy metal.{{sfn|Bukszpan|Dio|2003|p=288}} Heavy metal's acid rock origins can further be seen in the loud acid rock of groups such as [[Steppenwolf (band)|Steppenwolf]], who contributed their song "[[Born to Be Wild]]" to the [[Easy Rider (soundtrack)|soundtrack]] of the 1969 film ''[[Easy Rider]]'', which itself glamorized the genre.{{sfn|Browne|Browne|2001|p=8}} Ultimately, Steppenwolf and other acid rock groups such as Cream, the Jimi Hendrix Experience, and [[Led Zeppelin]] paved the way for the electrified, bluesy sound of early heavy metal.{{sfn|Kirkpatrick|2011|pp=27–28}}

[[File:Sabs.jpg|thumb|right|[[Black Sabbath]], 1970]]

[[Coven (band)|Coven]] is an American [[rock music|rock]] band formed in [[Chicago]] in the late 1960s. They had a top 40 hit in 1971 with the song "[[One Tin Soldier]]", the theme song of the movie ''[[Billy Jack]].''In addition to pioneering [[occult rock]] with lyrics and aesthetics that explicitly dealt in themes of [[Satanism]] and [[witchcraft]], they are recognized by [[Heavy metal music|metal]] fans and metal historians as being the band that introduced the "[[Sign of the horns]]" to rock, metal and pop culture, as seen on their 1969 debut album release ''[[Witchcraft Destroys Minds & Reaps Souls]]''.<ref>{{Cite web |date=August 18, 2021 |title=The Forgotten Mother of Metal Music and Birth of the "Devil's Horns" |url=https://atomicredhead.com/2021/08/18/the-forgotten-mother-of-metal-music-and-birth-of-the-devils-horns/ |access-date=June 15, 2023 |website=Atomic Redhead |language=en-US}}</ref><ref>{{Cite web |last=Trapp |first=Philip |date=April 21, 2021 |title=Where Did Metal's 'Devil Horns' Hand Gesture Really Come From? |url=https://loudwire.com/where-did-metal-devil-horns-hand-come-from/ |access-date=June 15, 2023 |website=Loudwire |language=en}}</ref> By the early 1970s, bands such as Deep Purple, Led Zeppelin and [[Black Sabbath]] combined the loud, raw distortion of acid rock with [[occult]] lyrics, further forming a basis for the genre now known as "heavy metal".{{sfn|Browne|Browne|2001|p=687}} At a time when rock music began to turn back to [[roots rock|roots]]-oriented [[soft rock]], many acid rock groups instead evolved into heavy metal bands.{{sfn|Hoffmann|2004|p=1725}} As its own movement, heavy metal music continued to perpetuate characteristics of acid rock bands into at least the 1980s,{{sfn|Dasher|1985|p=67}} and traces of psychedelic rock can be seen in the musical excesses of later metal bands.{{sfn|Hoffmann|2004|p=1725}} In the 1990s, the [[stoner metal]] genre combined acid rock with other hard rock genres such as [[grunge]], updating the heavy riffs and long jams found in the acid rock and psychedelic-influenced metal of bands such as Black Sabbath, Blue Cheer, [[Hawkwind]], and [[Blue Öyster Cult]].<ref name=AMStonerrock/>

In addition to hard rock and heavy metal, acid rock also gave rise to the [[progressive rock]] movement.{{sfn|Godfrey|Leigh|1998|p=2}} In the 1970s, elements of psychedelic music split into two notable directions, evolving into the hard rock and heavy metal of Black Sabbath, Deep Purple, and Led Zeppelin on one side and into the progressive rock of bands such Pink Floyd and [[Yes (band)|Yes]] on the other.{{sfn|Henderson|Stacey|2014|p=539}} Bands such as Yes, Pink Floyd, [[King Crimson]], and [[Emerson, Lake, and Palmer]] kept the psychedelic musical movement alive for some time, but eventually moved away from drug-themed music towards experiments in electronic music and the addition of [[classical music]] themes into rock music.{{Sfn|Browne|Browne|2001|p=8}}

==List of artists==
{{Main|List of acid rock artists}}

==Footnotes==
{{reflist|group=nb}}

==References==
{{Reflist|20em}}

==Bibliography==
{{refbegin|30em}}
* {{cite book|last1=Beck|first1=John H.|title=Encyclopedia of Percussion|date=2013|publisher=Routledge|url=https://books.google.com/books?id=8U83AgAAQBAJ&q=%22acid+rock%22+%22harder%22&pg=PA335|isbn=978-1-317-74768-0}}
* {{cite book|last=Bill|first=J. Brent|title=Rock and Roll|url=https://books.google.com/books?id=BpToW0RxpEUC|year=1984|publisher=F.H. Revell Co.|isbn=978-0-8007-5156-2}}
* {{cite book|last1=Bisbort|first1=Alan|last2=Puterbaugh|first2=Parke|title=Rhino's Psychedelic Trip|date=2000|publisher=Hal Leonard Corporation|isbn=9780879306267|url=https://books.google.com/books?id=xsa9NUlj9FsC&q=%22acid+rock%22+rawer&pg=PA31}}
* {{cite book|last1=Brend|first1=Mark|title=Strange Sounds: Offbeat Instruments and Sonic Experiments in Pop|date=2005|publisher=Hal Leonard Corporation|isbn=9780879308551|url=https://books.google.com/books?id=m6KRDxYOp4UC&q=%22acid+rock%22+%22harder%22&pg=PT91}}
* {{cite book|last1=Brown|first1=Charles T.|title=Music U.S.A.: America's country & western tradition|date=1986|publisher=Prentice-Hall|url=https://archive.org/details/musicusaamericas0000brow|url-access=registration|quote=san francisco sound heavy metal.}}
* {{cite book|last1=Browne|first1=Ray Broadus|last2=Browne|first2=Pat|title=The Guide to United States Popular Culture|date=2001|publisher=Popular Press|isbn=9780879728212|url=https://books.google.com/books?id=U3rJxPYT32MC&q=%22acid+rock%22+%22heavy+metal%22&pg=PA8}}
* {{cite book|last1=Bukszpan|first1=Daniel|last2=Dio|first2=Ronnie James|title=The Encyclopedia of Heavy Metal|date=2003|publisher=Barnes & Noble Publishing|isbn=9780760742181|url=https://books.google.com/books?id=YaDDsg0H35gC&q=%22acid+rock%22+%22heavy+metal%22+encyclopedia+metal&pg=PT275}}
* {{cite book|last1=Case|first1=George|title=Out of Our Heads: Rock 'n' Roll Before the Drugs Wore Off|date=2010|publisher=Hal Leonard Corporation|isbn=9780879309671|url=https://books.google.com/books?id=4neuLF3p5ykC&q=nuggets+%22acid+rock%22&pg=PA265}}
* {{cite book|last1=Dasher|first1=Richard T.|title=History of Rock Music|date=1985|publisher=J. Weston Walch|url=https://books.google.com/books?id=e3RLAAAAYAAJ&q=%22san+francisco+sound%22+%22tonal+distortion%22}}
* {{cite book|first=Jim|last=DeRogatis|author-link=Jim DeRogatis|title=Turn on Your Mind: Four Decades of Great Psychedelic Rock|url=https://books.google.com/books?id=U7cQmRsLgN8C|year=2003|publisher=Hal Leonard Corporation|isbn=978-0-634-05548-5}}
* {{cite book|last=Drabløs|first=Per Elias|title=The Quest for the Melodic Electric Bass: From Jamerson to Spenner|url=https://books.google.com/books?id=ODKrCwAAQBAJ|year=2016|publisher=Routledge|isbn=978-1-317-01837-7}}
* {{cite book|last1=Eder|first1=Bruce|title=All Music Guide: The Definitive Guide to Popular Music|date=2001|publisher=Hal Leonard Corporation|url=https://books.google.com/books?id=xR7MdpuSlAEC&q=nuggets+%22acid+rock%22&pg=PT68|isbn=978-0-87930-627-4}}
* {{cite book|last1=Freeman|first1=Alan|last2=Freeman|first2=Steve|title=The Crack in the Cosmic Egg: Encyclopedia of Krautrock, Kosmische Musik & Other Progressive, Experimental & Electronic Musics from Germany|date=1996|publisher=Audion|isbn=9780952950608|url=https://books.google.com/books?id=aoInAQAAIAAJ&q=%22acid+rock%22+%22hard%22+psychedelic}}
* {{cite book|last1=Frith|first1=Simon|title=Popular Music: Music and identity, Volume 4|date=2004|publisher=Psychology Press|url=https://books.google.com/books?id=5i6i5vb8A1gC&q=%22acid+rock%22+%22nuggets%22&pg=PA98|isbn=978-0-415-33270-5}}
* {{cite book|last=Gammond|first=Peter|title=The Oxford Companion to Popular Music|url=https://archive.org/details/oxfordcompaniont00gamm|url-access=registration|year=1991|publisher=Oxford University Press|isbn=978-0-19-311323-7}}
* {{cite book|last1=Godfrey|first1=Donald. A|last2=Leigh|first2=Frederic A.|title=Historical Dictionary of American Radio|date=1998|publisher=Greenwood Publishing Group|url=https://books.google.com/books?id=4l_2kkv5aeMC&q=acid+rock+%22progressive+rock%22&pg=PA2|isbn=978-0-313-29636-9}}
* {{cite book|last1=Henderson|first1=Lol|last2=Stacey|first2=Lee|title=Encyclopedia of Music in the 20th Century|date=2014|publisher=Routledge|url=https://books.google.com/books?id=m8W2AgAAQBAJ&q=%22acid+rock%22+%22hard+rock%22+%22heavy+metal%22&pg=PA539|isbn=978-1-135-92946-6}}
*{{cite book|last1=Hoffmann|first1=Frank|title=Encyclopedia of Recorded Sound|date=2004|publisher=Routledge|url=https://books.google.com/books?id=-FOSAgAAQBAJ&q=%22encyclopedia+of+recorded+sound%22+%22acid+rock%22|isbn=978-1-135-94950-1}}
* {{cite book|editor-last=Holm-Hudson|editor-first=Kevin|title=Progressive Rock Reconsidered|url=https://books.google.com/books?id=JQCPAQAAQBAJ&pg=PA275|year=2013|publisher=Routledge|isbn=978-1-135-71022-4}}
* {{cite book|last=Hull|first=Robot A.|title=The Sound and the Fury: 40 Years of Classic Rock Journalism: A Rock's Backpages Reader|url=https://books.google.com/books?id=VoUOTSUSVZoC|year=2003|publisher=Bloomsbury USA|isbn=978-1-58234-282-5|chapter=Sound and Visions: Psychedelia|editor-last1=Hoskyns|editor-first1=Barney|editor-link1=Barney Hoskyns|orig-year=1981}}
* {{cite book|last1=Jasinski|first1=Laurie E.|title=Handbook of Texas Music|date=2012|publisher=Texas A&M University Press|url=https://books.google.com/books?id=CE8xiT3pV6QC&q=%22acid+rock%22+%22heavier%22&pg=PT1355|isbn=978-0-87611-297-7}}
* {{cite book|last=Joyson|first=Vernon|title=The Acid Trip: A Complete Guide to Psychedelic Music|date=1984|publisher=Babylon Books|location=Todmorden, England|isbn=978-0-907188-24-7|url=https://books.google.com/books?id=tQc5AQAAIAAJ}}
* {{cite book|last1=Kirkpatrick|first1=Rob|title=1969: The Year Everything Changed|date=2011|publisher=Skyhorse Publishing|isbn=9781616080556|url=https://books.google.com/books?id=5DOOt-7lbQEC&q=%22acid+rock%22+%22heavy+metal%22&pg=PA27}}
* {{cite book|last1=Knowles|first1=Christopher|title=The Secret History of Rock 'n' Roll|date=2010|publisher=Cleis Press|isbn=9781573444057|url=https://books.google.com/books?id=-rLGAgAAQBAJ&q=%22deep+purple%22+%22acid+rock%22&pg=PA199}}
* {{cite book|last=Kuhn|first=Laura Diane|title=Baker's Student Encyclopedia of Music: A-G|url=https://archive.org/details/isbn_9780028654164|url-access=registration|quote=acid rock baker's.|year=1999|publisher=Schirmer Books|isbn=978-0-02-865415-7}}
*{{cite book|last1=Larson|first1=Tom|title=History of Rock and Roll|date=2004|publisher=Kendall Hunt|isbn=9780787299699|url=https://books.google.com/books?id=vGJ7XmA8rjIC&q=jefferson+airplane+%22acid+rock%22&pg=PA140}}
* {{cite book |last=Lucky |first=Jerry |title=The Psychedelic Rock Files |year=2003 |publisher=Collector's Guide Publishing Inc |isbn=1-896522-97-1 |url-access=registration |url=https://archive.org/details/psychedelicrockf00luck }}
*{{cite book|last1=Luft|first1=Eric v.d.|title=Die at the Right Time!: A Subjective Cultural History of the American Sixties|date=2009|publisher=Gegensatz Press|isbn=9781933237398|url=https://books.google.com/books?id=7ryvnZiTBAAC&q=die+at+the+right+time+%22acid+rock%22&pg=PA173}}
* {{cite book|last=McEneaney|first=Kevin T.|title=Tom Wolfe's America: Heroes, Pranksters, and Fools|url=https://books.google.com/books?id=8pNzCQAAQBAJ&pg=PA45|year=2009|publisher=ABC-CLIO|isbn=978-0-313-36545-4}}
* {{cite book|last=McLauchlin|first=Luke|title=Acid Rock: LSD, Psychedelc Rock, and the San Francisco Sound|url=https://books.google.com/books?id=kekOswEACAAJ|year=2015|publisher=Ipicturebooks|isbn=978-1-329-25654-5}}
* {{cite book|last1=Misiroglu|first1=Gina|title=American Countercultures: An Encyclopedia of Nonconformists, Alternative Lifestyles, and Radical Ideas in U.S. History|date=2015|publisher=Routledge|isbn=9781317477297|url=https://books.google.com/books?id=j4KsBwAAQBAJ&q=%22acid+rock%22+music&pg=PA10}}
* {{cite book|last1=Moore|first1=Hank|title=Houston Legends: History and Heritage of Dynamic Global Capitol|date=2015|publisher=Morgan James Publishing|isbn=9781630474690|url=https://books.google.com/books?id=UCLbBQAAQBAJ&q=%22acid+rock%22+%2213th+floor%22&pg=PA126}}
*{{cite book |first=Mark A. |last=Nobles |title=Fort Worth's Rock and Roll Roots |url=https://books.google.com/books?id=TLDefXZ98poC&pg=PA32 |date=2012 |publisher=Arcadia Publishing |isbn=978-0-7385-8499-7 }}
* {{cite book|last1=Perone|first1=James E.|title=Songs of the Vietnam Conflict|date=2001|publisher=Greenwood Publishing Group|isbn=9780313315282|url=https://books.google.com/books?id=HHQqoUcbd8gC&q=%22acid+rock%22+%22british%22+hendrix+vietnam&pg=PA56|access-date=27 April 2016}}
*{{cite book |last=Reynolds |first=Simon |author-link=Simon Reynolds |title=Energy Flash: A Journey Through Rave Music and Dance Culture |url=https://books.google.com/books?id=o5wGKnxoTAwC&pg=PT150 |year=2012 |publisher=Counterpoint LLC |isbn=978-1-59376-477-7 }}{{Dead link|date=July 2023 |bot=InternetArchiveBot |fix-attempted=yes }}
* {{cite book|author=Rolling Stone Magazine Staff |chapter=Talking with the Legend of Rock and Roll (Jerry Garcia) |title=The Rolling Stone Interviews: 1967–1980 |date=15 September 1989 |publisher=Macmillan |isbn=0-312-03486-5}}
* {{cite book|last1=Romano|first1=Will|title=Mountains Come Out of the Sky: The Illustrated History of Prog Rock|date=2010|publisher=Backbeat Books|location=Milwaukee, WI|isbn=978-0-87930-991-6|url=https://books.google.com/books?id=2lVMAgAAQBAJ|page=17}}
* {{cite book|last1=Rood|first1=Karen Lane|title=American culture after World War II|date=1994|publisher=Gale Research|isbn=9780810384811|url=https://archive.org/details/americanculturea00rood|url-access=registration|quote=but its influence is apparent in the heavy-metal sound.}}
* {{cite book|last1=Unterberger|first1=Richie|title=All Music Guide to Rock: The Definitive Guide to Rock, Pop, and Soul|date=2002|publisher=Hal Leonard Corporation|isbn=9780879306533|url=https://books.google.com/books?id=1-pH4i3jXvAC&q=%22ultimate+spinach%22+%22acid+rock%22&pg=PA1172}}
* {{cite book|last1=Weinstein|first1=Deena|title=Heavy Metal: The Music and Its Culture|date=2009|publisher=Da Capo Press|isbn=9780786751037|url=https://books.google.com/books?id=3ag-T6ppMowC&q=%22acid+rock%22+%22heavy+metal%22&pg=PA16}}
* {{cite book|last1=Waksman|first1=Steve|title=Instruments of Desire: The Electric Guitar and the Shaping of Musical Experience|date=2001|publisher=Harvard University Press|isbn=9780674005471|url=https://books.google.com/books?id=-DWxyYapaBwC&q=%22acid+rock%22+%22hard+rock%22+%22heavy+metal%22&pg=PA262}}
* {{cite book|last=Wolfe |first=Tom |title=The Electric Kool-Aid Acid Test |year=1968 |publisher=Black Swan |isbn=0-552-99366-2}}
* {{Cite book|title = Rockin' in time: a social history of rock-and-roll|last = Szatmary|first = David P.|publisher = Pearson|year = 2014}}
* {{cite book|title=Academic American Encyclopedia|date=1985|publisher=Grolier|edition=Vol 16}}
*{{cite book|ref=fuzz|title=Fuzz, Acid and Flowers: A Comprehensive Guide to American Garage, Psychedelic and Hippie Rock (1964–1975)|year=1997 |publisher=Borderline }}
{{refend}}
{{Psychedelic music}}
{{Rock music}}

{{DEFAULTSORT:Acid Rock}}
[[Category:Acid rock| ]]
[[Category:Psychedelic rock]]
[[Category:20th-century music genres]]
[[Category:1960s in American music]]
[[Category:1960s neologisms]]
[[Category:Rock music genres]]
[[Category:American styles of music]]