One could raise the argument that there are better Beatles albums, but there's no denying the impact that Sgt. Pepper's Lonely Hearts Club Band had on the evolution of pop music as a whole. Simply put, after this record, everyone had to aim higher. The band had eagerly embraced the studio as an instrument on Revolver, but here they go all in, lavishing tunes like the title track, "Lucy In The Sky With Diamonds" and the transporting "A Day In The Life" with elaborate orchestration and production trickery that would be utterly impossible to duplicate live at the time. But that's kind of the genius of Sgt. Pepper's: it was never about catching a reflection of live performance on record, it was about elevating the album to an art form in itself. They might not have been the first band to do that, granted, but they were the band that definitively established it as the thing to do.