The Beatles' Revolver celebrates its 50th anniversary this year - an album many consider not just to be the band's greatest, but the greatest record ever made.

Released August 5, 1966, Revolver defines the second half of The Beatles' career showing how they made a seismic shift from a singles oriented band into masters of the recording studio.

Following on a mere six months from previous album Rubber Soul, Revolver saw the band move away from their beat-pop sound into a world of psychedelia, classical orchestration, tape loops and free-wheeling rock and roll.

Crucially, the album saw George Harrison step forward as a major song-writing force contributing three of the 14 tracks while imbuing the record with his love affair with Indian culture.

From the opening riff of Taxman through to closer Tomorrow Never Knows - possibly the most influential track of all-time - Revolver is in a select bunch of contemporary pop albums which can be regarded forever as a timeless classic.

Here's 14 awesome Revolver facts

1. The album artwork won Album Cover Of The Year at the 1966 Grammys

Created by German-born bass player and artist Klaus Voormann using personal photos supplied by the band - he subtly also works his own name into George Harrison's hair.

The album's title is said to refer to the revolving motion of a record as it is played on a turntable with previous title Abracadabra rejected after discovering it had already been used. Other suggestions included Magic Circles, Beatles on Safari and Pendulum.

2. Tomorrow Never Knows was originally called 'Mark I'

Is there a more influential song than this? Debatable - but there's simply no denying it's a landmark in pop culture.

Lennon's lyrics were inspired by Timothy Leary's book The Psychedelic Experience: A Manual Based on the Tibetan Book of the Dead while the track features prominent drums and an array of processed vocals, sitars, reversed cymbals and a droning tanpura.

The key five tape loops contain: a "laughing" voice (the 'seagull' sound), an orchestral drone, an electric guitar reversed and played at double-speed, a Mellotron and a sitar - again played backward and speeded up.

The track has subsequently inspired whole movements of pop and dance culture - most notably with the Chemical Brothers insisting the song shaped their career; with chart-topping Setting Sun a direct tribute.

3. The band wanted to record and take inspiration from Memphis' Stax sound.

Brian Epstein attempted to book Stax's studio in Memphis and later Motown in Detroit as The Beatles were so taken with their influential sounds.

However, plans were aborted after fans descended on the facilities - instead the McCartney penned Got To Get You Into My Life is an ode to the bold brassy soulful sound.

Five session players were brought in to produce the brass section and were paid £18 each.

Paul McCartney later said: the song was about marijuana, "I wrote it when I had first been introduced to pot - like someone else might write an ode to chocolate or a good claret."

4. John's love of sleeping and staying in bed not unsurprisingly inspired I'm Only Sleeping.

The track's lyrics were originally written on the back of an envelope for a letter reminding him to pay his radio license.

The original lyrics contain the phrase "Got to get to sleep," left out of the final version and the phase "float downstream," was changed to "float upstream."

Journalist and friend of Lennon Maureen Cleave said of him: "He can sleep almost indefinitely, he is probably the laziest person in England."

To which John replied: "Physically lazy - I don't mind writing or reading or watching or speaking, but sex is the only physical thing I can be bothered with any more."

During the break before the second bridge Lennon can be heard saying, "Yawn, Paul", followed seconds later by a big yawn.

5. NASA love Good Day Sunshine.

Such is its radiating optimism, the Paul McCartney-penned song Good Day Sunshine has been played as the start-up music on multiple Space Shuttle missions.

So much so McCartney played the song live to the crew of the International Space Station in November 2005 - in the first-ever concert link-up to the space station.

Also, George Martin was sequestered to perform the piano solo.

6. She Said She Said was inspired by John Lennon's adverse reaction to an LSD trip.

Manager Brian Epstein had rented a flat in the Beverly Hills mountains and while there singer Joan Baez, The Byrds, actor Peter Fonda and Playboy models joined them.

During one particular conversation Fonda relayed an anecdote about a self-inflicted gun shot wound saying, "I know what it's like to be dead."

Lennon, who was enjoying the effects of the acid, reportedly snapped back: "Listen mate, shut up about that stuff - you're making me feel like I've never been born." And so the song began to take shape.

7. Only Paul and Ringo feature on For No One and it was written in a Swiss Alps ski resort bathroom.

Another indication that The Beatles were working less as a band, For No One features Ringo on percussion and Paul playing bass guitar, piano and clavichord.

Alan Civil played the French horn solo. Recording engineer Geoff Emerick regarded Civil as the best horn player in London and the performance was deemed so good it pushed the instrument through barriers previously unexplored.

Remarking about the lyrics, Paul said: "I suspect it was about another argument." The song finishes with the line, "a love that should have lasted years."

8. Revolver took 300 hours of studio time to create.

The recording of the album was extensive, roughly three times the amount of time for Rubber Soul - an astronomical amount for a record in 1966.

Sessions took place at the intimate studio three in Abbey Road and key to the recording was EMI engineer Ken Townsend's pioneering work double-tracking production technique.

Townsend used two linked tape recorders to automatically create a doubled vocal track when the standard method had been to double the vocal by singing the same piece twice onto a multi track tape - something John Lennon particularly disliked.

ADT soon became a standard pop production technique. Also recorded during the Revolver sessions were Paperback Writer and classic B-side Rain.

9. Revolver's release was somewhat overshadowed by John Lennon's 'Bigger Than Jesus' comment.

John Lennon's famous quote was originally made in March 1966 during an interview with Maureen Cleave for the London Evening Standard - and it drew no public reaction.

It was only when Datebook, a US teen magazine, quoted Lennon's comments five months later that extensive protests broke out in the Southern United States leading to some radio stations banning Beatles songs, their records publicly burned, threats were made - plus picketing by the Ku Klux Klan.

The Vatican issued a public denouncement of Lennon's comments

His comment in full reads: "Christianity will go. It will vanish and shrink. I needn't argue about that; I'm right and I'll be proved right. We're more popular than Jesus now; I don't know which will go first - rock and roll or Christianity."

Despite the uproar, the record spent 34 weeks on the UK Albums Chart, seven at number one while topping the Billboard chart for six weeks.

10. Although never confirmed Dr Robert is thought to be about physician Dr. Robert Freymann.

Manhattan-based, German-born Freymann was known to New York's artists and wealthier citizens for his vitamin B-12 injections and liberal doses of amphetamine.

Freymann's celebrity patients were said to include Jackie Kennedy before he lost his medical license in 1975.

Paul McCartney described the meaning saying, "There's some fellow in New York and you can get everything off him; any pills you want - he just kept New York high. That's what Dr. Robert is all about, just a pill doctor who sees you all right."

John Lennon's closing words on the track are "OK Herb" at the very last second of the song.

11. Eleanor Rigby was the first Beatles track to contain no guitar at all.

In fact, none of The Beatles played instruments on it with Paul taking lead vocals and John and George contributing harmonies on backing vocals.

The song saw producer George Martin employ a classical string ensemble including four violins, two violas and two cellos.

Interestingly, all four Beatles contributed lyrics - Paul the majority and lead song-writing credit with George coming up with the "Ah, look at all the lonely people" hook and Ringo the line "writing the words of a sermon that no one will hear".

12. Here, There and Everywhere is The Beatles' response to The Beach Boys' God Only Knows.

There was healthy competition between both bands who were reshaping pop music and McCartney, having attended a listening party for the Beach Boys' Pet Sounds album was inspired to pen Here, There and Everywhere.

Paul lists it among his personal favourites ever written - a claim backed up by George Martin and Lennon. Art Garfunkel names it his favourite ever track.

In 2000, Mojo ranked it 4th in the magazine's list of the greatest songs of all time.

Meanwhile, in TV series Friends the song is played on steel drums when Phoebe walks down the aisle during her wedding.

McCartney's My Love was also used in a Friends wedding sequence when Chandler and Monica married.

13. The guitar solo on Taxman was played by Paul McCartney.

Hours were poured into the recording of the Harrison-penned track and after much frustration from producer George Martin it was decided that Paul McCartney would play the savage guitar solo as George struggled to nail it.

This understandably caused much upset to Harrison who reportedly left the studio in a sulk yet talking about the track in 1987, Harrison conceded it was a wise move to have Paul lay down the guitar part as he brought an Eastern flavour to the proceedings.

In Ian MacDonald's Revolution In The Head he wrote: "Paul’s solo was stunning in its ferocity - his guitar playing had a fire and energy that his younger band mates rarely matched - and was accomplished in just a take or two.”

George wrote the song out of anger towards how much money he was paying to the taxman, with overdubbed backing vocals mentioning “Mister [Harold] Wilson” and “Mister [Edward] Heath."

14. Yellow Submarine was the only British Beatles single to feature Ringo on lead vocals.

According to McCartney the song began as being about different coloured submarines, but evolved to include only a yellow one - and he wrote it while staying at girlfriend Jane Asher's parents' house.

Brian Jones, Patti Boyd, Marianne Faithful and Donovan reportedly added backing vocals - though they are uncredited.

In 1984 a 51 feet (16m) long yellow submarine metal sculpture was built by Cammell Laird shipyard apprentices and was used at Liverpool's International Garden Festival.

In 2005 it was placed outside Liverpool's John Lennon Airport, where it remains.

* Merseyside musicians including, She Drew The Gun, Thom Morecroft and LIMF-backed Eleanor Nelly will perform Revolver in full as part of the 50th anniversary at Leaf on Bold Street on Friday, August 5.