Revolver (Beatles album) group collective since 1962, and gave them an unprecedented amount of time to prepare for a new album. Writing in "The Beatles Forever", Nicholas Schaffner cites 1966 as the start of the band's "'psychedelic' period" and adds: "That adjective 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 experimentation with the drug LSD since the spring of 1965.<ref name="Clerk/Uncut"> Available at Rock's Backpages (subscription required).</ref>
Revolver (Beatles album) North America, where three of its tracks instead appeared on the June 1966 release "Yesterday and Today". The Beatles recorded the album following a three-month break from professional commitments at the start of 1966, and during a period when London was feted as the era's cultural capital. The songs reflect the influence of psychedelic drugs such as LSD and the increasing sophistication of the Beatles' lyrics to address themes including death and transcendence from material concerns. With no thoughts of reproducing their new material in concert, the band made liberal use of studio techniques such as varispeeding, reversed tapes, close