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
Sgt. Pepper's Lonely Hearts Club Band placement of random gibberish in the run-out groove, is one of the album's defining features. In Mark Lewisohn's opinion, "Sgt. Pepper" represents the group's last unified effort, displaying a cohesion that would begin deteriorating immediately following the album's completion and that had entirely disappeared by the release of "The Beatles" in 1968. Martin recalled in 1987 that throughout the making of "Sgt. Pepper", "There was a very good spirit at that time between all the Beatles and ourselves. We were all conscious that we were doing something that was great." He said that while McCartney effectively led the project, and