Paul McCartney February 1967, and the LP followed in June. McCartney's "She's Leaving Home" was an orchestral pop song. MacDonald described the track as "[among] the finest work on "Sgt. Pepper"—imperishable popular art of its time". Based on an ink drawing by McCartney, the LP's cover included a collage designed by pop artists Peter Blake and Jann Haworth, featuring the Beatles in costume as the Sgt. Pepper's Lonely Hearts Club Band, standing with a host of celebrities. The heavy moustaches worn by the Beatles reflected the growing influence of hippie style trends on the band, while their clothing "spoofed the vogue in
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