progressive rock and world music. The album cover, designed by Klaus Voormann, combined Aubrey Beardsley-inspired line drawing with photo collage and won the 1967 Grammy Award for Best Album Cover, Graphic Arts. Aided by the 1987 international CD release, which standardised its content to the original Parlophone version, Revolver has surpassed Sgt. Pepper's Lonely Hearts Club Band in many critics' estimation as the Beatles' best album. It was ranked first in the 1998 and 2000 editions of Colin Larkin's book All Time Top 1000 Albums and third in the 2003 and 2012 editions of Rolling Stone magazine's list of the "500 Greatest Albums of All Time". It has been certified double platinum by the BPI and 5× platinum by the RIAA. A remixed and expanded edition of the album was released in 2022. Background In December 1965, the Beatles' Rubber Soul album was released to wide critical acclaim. According to author David Howard, the limits of pop music "had been raised into the stratosphere" by the release, resulting in a shift in focus away from singles to creating albums of consistently high quality. The following January, the Beatles carried out overdubs on live recordings taken from their 1965 US tour, for inclusion in the concert film The Beatles at Shea Stadium. The group's manager, Brian Epstein, had intended that 1966 would then follow the pattern of the previous two years, in terms of the band making a feature film and an accompanying album, followed by concert tours during the summer months. After the Beatles vetoed the proposed film project, the time allocated for filming became a further three months free of professional engagements. This was the longest period the band members had experienced outside the group collective since 1962, and it defied convention that pop acts should be almost permanently working. The group thereby had an unprecedented amount of time to prepare for a new album. Beatles biographer Nicholas Schaffner cites 1966 as the start of the band's "psychedelic period", as do musicologists Russell Reising and Jim LeBlanc. Schaffner adds: "That adjective [psychedelic] implies not only the influence of certain mind-altering chemicals, but also the freewheeling spectrum of wide-ranging colors that their new music seemed to evoke." Music journalist Carol Clerk describes Revolver as having been "decisively informed by acid", following John Lennon and George Harrison's continued use of the drug LSD since the spring of 1965. Through these experiences,