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>
The Beatles' 1966 US tour The Beatles' 1966 US tour The Beatles staged their third concert tour of America in August 1966, and it was the last commercial tour they undertook. Lasting a total of 19 performances, with 17 shows in American venues and two in Canada, it was plagued with backlash regarding the controversy of John Lennon's remark about the Beatles being "more popular than Jesus", death threats, and the band's own dissatisfaction with the noise levels and their ability to perform live. Although it was a commercial success, ticket sales had declined since the group's previous visit, in August 1965. Late in the