The Beatles (Proto-Metal)

Heavy metal's quintessential guitar style, built around distortion-heavy riffs and power chords, traces its roots to early 1950s Memphis blues guitarists such as Joe Hill Louis, Willie Johnson, and particularly Pat Hare,^[109][110] who captured a "grittier, nastier, more ferocious electric guitar sound" on records such as James Cotton's "Cotton Crop Blues" (1954);^[110]the late 1950s instrumentals of Link Wray, particularly "Rumble" (1958);^[111] the early 1960s surf rock of Dick Dale, including "Let's Go Trippin'" (1961) and "Misirlou" (1962); and The Kingsmen's version of "Louie Louie" (1963) which made it a garage rock standard.^[112]

Cream performing on the Dutch television program Fanclub in 1968.

However, the genre's direct lineage begins in the mid-1960s. American blues music was a major influence on the early British rockers of the era. Bands like The Rolling Stones and The Yardbirds developed blues rock by recording covers of classic blues songs, often speeding up the tempos. As they experimented with the music, the UK blues-based bands—and the U.S. acts they influenced in turn—developed what would become the hallmarks of heavy metal, in particular, the loud, distorted guitar sound.^[31] The Kinks played a major role in popularising this sound with their 1964 hit "You Really Got Me".^[113]

In addition to The Kinks' Dave Davies, other guitarists such as The Who's Pete Townshend and The Yardbirds' Jeff Beck were experimenting with feedback.^[114][115] Where the blues rock drumming style started out largely as simple shuffle beats on small kits, drummers began using a more muscular, complex, and amplified approach to match and be heard against the increasingly loud guitar.^[116] Vocalists similarly modified their technique and increased their reliance on amplification, often becoming more stylized and dramatic. In terms of sheer volume, especially in live performance, The Who's "bigger-louder-wall-of-Marshalls" approach was seminal.^[117]

The combination of blues rock with psychedelic rock and acid rock formed much of the original basis for heavy metal.^[118]The variant or subgenre of psychedelic rock often known as "acid rock" was particularly influential on heavy metal; acid rock is often defined as a heavier, louder, or harder variant of psychedelic rock,^[119] or the more extreme side of the psychedelic rock genre, frequently containing a loud, improvised, and heavily distorted guitar-centered sound. Acid rock has been described as psychedelic rock at its "rawest and most intense," emphasizing the heavier qualities associated with both the positive and negative extremes of the psychedelic experience rather than only the idyllic side of psychedelia.^[120]American acid rock garage bands such as the 13th Floor Elevators epitomized the frenetic, heavier, darker and more psychotic sound of acid rock, a sound characterized by droning guitar riffs, amplified feedback, and guitar distortion, while the 13th Floor Elevators' sound in particular featured yelping vocals and "occasionally demented" lyrics.^[121] Frank Hoffman notes that: "Psychedelia was sometimes referred to as 'acid rock'. The latter label was applied to a pounding, hard rockvariant 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 acts."^[122]

One of the most influential bands in forging the merger of psychedelic rock and acid rock with the blues rock genre was the British power trio Cream, who derived a massive, heavy sound from unison riffing between guitarist Eric Clapton and bassist Jack Bruce, as well as Ginger Baker's double bass drumming.^[123] Their first two LPs, Fresh Cream (1966) and Disraeli Gears (1967), are regarded as essential prototypes for the future style of heavy metal. The Jimi Hendrix Experience's debut album, Are You Experienced (1967), was also highly influential. Hendrix's virtuosic technique would be emulated by many metal guitarists and the album's most successful single, "Purple Haze", is identified by some as the first heavy metal hit.^[31] Vanilla Fudge, whose first album also came out in 1967, has been called "one of the few American links between psychedelia and what soon became heavy metal",^[124] and the band has been cited as an early American heavy metal group.^[125] On their self-titled debut album, Vanilla Fudge created "loud, heavy, slowed-down arrangements" of contemporary hit songs, blowing these songs up to "epic proportions" and "bathing them in a trippy, distorted haze."^[124]

During the late 1960s, many psychedelic singers, such as Arthur Brown, began to create outlandish, theatrical and often macabre performances; which in itself became incredibly influential to many metal acts.^{[126][127][128]} The American psychedelic rock band Coven, who opened for early heavy metal influencers such as Vanilla Fudge and the Yardbirds, portrayed themselves as practitioners of witchcraft or black magic, using dark—Satanic or occult—imagery in their lyrics, album art, and live performances. Live shows consisted of elaborate, theatrical "Satanic rites." Coven's 1969 debut album, Witchcraft Destroys Minds & Reaps Souls, featured imagery of skulls, black masses, inverted crosses, and Satan worship, and both the album artwork and the band's live performances marked the first appearances in rock music of the sign of the horns, which would later become an important gesture in heavy metal culture.^[129][130] At the same time in England, the band Black Widow were also among the first psychedelic rock bands to use occult and Satanic imagery and lyrics, though both Black Widow and Coven's lyrical and thematic influences on heavy metal were quickly overshadowed by the darker and heavier sounds of Black Sabbath.^[129][130]