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
Revolver (Beatles album) The 1987 international CD release standardised the album's content to the original Parlophone version. "Revolver" expanded the scope of pop music in terms of the range of musical styles used on the album, compositional form, and the lyrical content of its songs. The album was influential in advancing principles espoused by the 1960s counterculture and in inspiring the development of subgenres such as psychedelic rock, electronica, progressive rock and world music. Many music critics recognise it as the Beatles' best album, surpassing "Sgt. Pepper's Lonely Hearts Club Band". The album was ranked first in Colin Larkin's book "All-Time Top 1000