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 in India out with the Maharishi engendered a long-lasting suspicion that "they'd become faddists tipped into eccentric habits by unfathomable fame". Having given up touring in 1966, the trip to India was the last time all four Beatles travelled together. Their self-exploration through meditation and before that, LSD, led to each of them adopting a more individual focus, at the expense of band unity, through to the group's break-up in 1970. The acrimony within the band was evident during the recording of their 1968 double album "The Beatles" (also known as the "White Album"), when they recorded many of the songs written