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
Experimental pop experimental pop groups. According to "The New York Times", Barrett and his subsequent solo albums "became a touchstone for experimental pop musicians". By the late 1960s, highly experimental pop music, or sounds that expanded the idea of the typical popular song, was positively received by young audiences, which cultural essayist Gerald Lyn Early credits to bands like Cream, Traffic, Blood, Sweat & Tears, and "of course", the Beatles. Drummer John Densmore believed that the Doors were on the cutting-edge of experimental pop music until he listened to the Beatles' album "Sgt. Pepper's Lonely Hearts Club Band" (1967), which he described