The Beatles’ evolution from straightlaced pop-rockers to boundary-decimating musical pioneers was subtle and gradual, but changes that had been germinating below the surface started to break through to the light of day on Rubber Soul. For all intents and purposes, this is the fulcrum between the traditional Beatles and the experimental Beatles. It also kicked off a string of all-time classic LPs that, without even a pinch of hyperbole, changed rock ‘n’ roll forever. From here on out, there’d be no more covers (40 seconds of “Maggie Mae” notwithstanding), and every album would be recorded as a standalone project rather than cribbed together from disparate sessions. The band also tried out a new array of forms, arrangements, and chord progressions here, so those who have trouble telling the early hits apart should have no such trouble with Rubber Soul. “Norwegian Wood” alone would be a quantum leap even if George hadn’t taken up his sitar for the first time. Thematically, it’s darker, more ambiguous, and highly unsettling for anyone expecting more doe-eyed romance; structurally it trades the sound of prom slow dances for the influence of the young folk rabble-rouser Bob Dylan. (And, OK, they also included the ultimate prom slow dance with “In My Life.”) But it’d be selling this record’s advances short to limit them to just one song, or even just to focus on the typically progressive John Lennon’s contributions. Sheesh, Harrison has one sarcastic little ditty called “Think For Yourself” and another one that declares his independence from the ladies, so stick that in your shrill, shrieking kisser. Even Paul isn’t entirely stuck in his old ways if singing in French counts as broadening your horizons. Just kidding; Macca jams like “I’m Looking Through You” and “You Won’t See Me” are highly advanced specimens on an album full of them.