The Beatles’ sort of seventh album Revolver is one of the most important in the history of popular music. And on 5th August 2016, it turns fifty. After deviating from their usual sound in 1965 album Rubber Soul, Revolver marks a seismic shift in their style. Ditching live performances, the fab four set to utilise the studio to its full potential. Complete with a lot of drugs.

To understand the importance of Revolver, look no further than automatic double tracking or ADT. Before ADT, manual double tracking was used to create a chorused effect. This required a vocalist recording the same part twice, then playing those recordings back simultaneously. It was tedious and Lennon hated it. So, at his request, Abbey Road engineer Ken Townsend developed ADT. He used tape delay to play back two copies of the same track, one slightly after the other.

The Beatles were delighted and used it frequently on Revolver. It was later adopted across the industry. Norman Smith used it extensively on Pink Floyd’s 1967 debut The Piper at the Gates of Dawn. Simon & Garfunkel and The Jimi Hendrix Experience were among others to adopt it.

Revolver is one of the most important albums in the history of popular music

– Nathan Brooks

On Revolver, tracks like I’m Only Sleeping, Love You To, And Your Bird Can Sing and Doctor Robert used ADT on the vocals. On their respective stereo mixes, the two tracks were split between the two channels, creating the effect of separate vocals on each side. The technique wasn’t limited to vocals. The lead guitar on the first track Taxman used it, as did the backwards guitar on the final track Tomorrow Never Knows. Manual double tracking was only used occasionally. Tomorrow Never Knows’ vocals were produced with that technique, whilst Eleanor Rigby utilise both simultaneously.

Countless other techniques were used, like varispeeding, which involved recording sounds at tempos different to what they would become on the album. Tomorrow Never Knows used backwards tape recordings and tape loops and Paul McCartney’s bass guitar was recorded through a loudspeaker, rather than a microphone, significantly amplifying it. Meanwhile Ringo Starr’s bass drum was exaggerated by inserting a piece of clothing (dampening the sound), placing the microphone three inches away and compressing it via a Fairchild Limiter. This technique later proved to be very popular in the industry.

[The use of Indian classical music] made Revolver striking back in 1966. It was the first time foreign sounds had been introduced at this scale to mainstream rock audiences.

– Nathan Brooks

Revolver also signified the start of The Beatles’ psychedelic era. Lennon and Harrison’s experiments with psychedelics since the spring of 1965 were widely influential on this album. As a result, Revolver is dominated by Indian sounds. Like McCartney’s guitar solo on Taxman, or Harrison’s backwards guitar solo on I’m Only Sleeping. Love You To was heavily influenced by Indian classical music, complete with sitars, tablas and tamburas. Harrison also played an Indian inspired C drone on the tambura for Tomorrow Never Knows. This made Revolver striking back in 1966. It was the first time foreign sounds had been introduced at this scale to mainstream rock audiences.

The psychedelic influence extends further than the music though. Lennon lifted the mystical lyrics of Tomorrow Never Knows from The Psychedelic Experience: A Manual Based on the Tibetan Book of the Dead. Harrison credited drugs for the lyrics of Love You To, heavily influenced by Eastern philosophical concepts. Meanwhile She Said She Said features lyrics such as “I know what it’s like to be dead”. That lyric originated from a conversation with actor Peter Fonda, who technically died during surgery as a child. Some consider Harrison’s Taxman as a precursor to the 1970s punk movement, thanks to its abrasive, anti-establishment lyrics.

It’s the diversity on display here, be it musical or lyrical, that makes Revolver so appealing to anyone who comes across it.

– Nathan Brooks

McCartney’s contributions were less drug influenced, refusing to join in with Harrison and Lennon’s experiments. Despite describing Got to Get You Into My Life as an “ode to pot”, for the most part his lyrics are more conventional; inspired by experiences among London’s artistic community. Eleanor Rigby is a hauntingly lonely and melancholic song; emotions amplified by the beautifully harmonious double string quartet. McCartney’s other contributions include the devastatingly poignant For No One, chronicling the tragic end of a relationship, the bluesy Good Day Sunshine, and the upbeat children’s song Yellow Submarine. It’s the diversity on display here, be it musical or lyrical, that makes Revolver so appealing to anyone who comes across it.

Revolver is one of the most important steps forward in popular music. Through innovative technical advancements and boundless imagination, The Beatles created an album that’ll go on to define the music industry for years. It sounds rather good too.