Inspired by the painstaking craft (and great aural results) of Brian Wilson's Pet Sounds, the Beatles - fresh from their retirement from touring - set out to make a trippy "masterpiece". Very influential. The LP's song cycle (the Parlophone vinyl had no divisions between the songs) featured numerous overdubs and FX, and plenty of good songs. This was probably the soundtrack to 1967 and its "Summer of Love". Other innovations: the gatefold sleeve and the printed lyrics.