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 of Invention has also been cited as having influenced "Sgt. Pepper". According to the author Philip Norman, during the "Sgt. Pepper" recording sessions McCartney repeatedly stated: "This is our "Freak Out!"" The music journalist Chet Flippo states that McCartney was inspired to record a concept album after hearing "Freak Out!" Martin recalled that "Sgt. Pepper" "grew naturally out of "Revolver"", marking "an era of almost continuous technological experimentation". According to Geoff Emerick, the Beatles' recording engineer, the "major difference" between the two albums was that, with "Sgt. Pepper", there was no absolute deadline for completion. Sessions began on 24 November