Sgt. Pepper's Lonely Hearts Club Band album carried on the childhood and Liverpool theme with its circus and fairground effects, its pervading atmosphere of the traditional northern music hall that was in both its main creators' [McCartney and Lennon's] blood." "Sgt. Pepper" album cover was designed by the pop artists Peter Blake and Jann Haworth. Blake recalled of the concept: "I offered the idea that if they had just played a concert in the park, the cover could be a photograph of the group just after the concert with the crowd who had just watched the concert, watching them. If we did this by using cardboard
Sgt. Pepper's Lonely Hearts Club Band peers", he continues, "what was revolutionary was the sonic carpet that enveloped the ears and sent the listener spinning into other realms." Stephen Thomas Erlewine of AllMusic considers the album to be a refinement of "Revolver"s "previously unheard-of level of sophistication and fearless experimentation" and a work that combines a wide range of musical styles yet "Not once does the diversity seem forced". He concludes: "After "Sgt. Pepper", there were no rules to follow – rock and pop bands could try anything, for better or worse." In 1987, Anthony DeCurtis of "Rolling Stone" described "Sgt. Pepper" as the album that