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>
A Collection of Beatles Oldies of the Beatles' achievement just before the plunge into 'Strawberry Fields' and "Sgt. Pepper"".<ref name="Ginell/AM"></ref> According to a December 1971 report in "Billboard" on the preference for UK-pressed LPs among Los Angeles record-buyers, "A Collection of Beatles Oldies" was one of the most popular imported titles, and recognised as good value for its generous number of songs relative to the US industry standard. For many years after its release, the 1966 compilation remained the only British album to contain the Beatles' version of "Bad Boy". Although briefly available on the Music for Pleasure budget label, it was superseded by subsequent