Sgt. Pepper's Lonely Hearts Club Band "Being for the Benefit of Mr. Kite!" and "A Day in the Life". Producer George Martin and engineer Geoff Emerick helped realise the group's ideas by approaching the studio as an instrument, applying orchestral overdubs, sound effects and other methods of tape manipulation. Recording was completed on 21 April 1967. The cover, depicting the Beatles posing in front of a tableau of celebrities and historical figures, was designed by the British pop artists Peter Blake and Jann Haworth. "Sgt. Pepper" is regarded by musicologists as an early concept album that advanced the use of extended form in popular music while
Album era "A Christmas Gift for You from Phil Spector" (1963), the Beatles' "Rubber Soul" (1965), the Beach Boys' "Pet Sounds" (1966), the Mothers of Invention's "Freak Out!" (1966), and the Beatles' "Sgt. Pepper's Lonely Hearts Club Band" (1967). In reference to the Beatles' "Rubber Soul", "Revolver" (1966) and "Sgt. Pepper" and the Beach Boys' "Pet Sounds", writer Bill Martin noted: "In the wake of these albums, many rock musicians took up the 'complete album approach.'" "Rolling Stone" assistant editor Andy Greene felt that "Sgt. Pepper's" "was the beginning of the album era. It was the big bang of albums." According to