3. The Beatles, 'Revolver' (1966)
With Revolver, the Beatles and Martin continued to establish themselves as artists who would push the boundaries of what popular music is capable of. Continuing what they started on Rubber Soul, the LP was psychedelic and arty while still remaining accessible and dynamic. Tracks like "Yellow Submarine" and "Tomorrow Never Knows" laid the groundwork for the trippy excursion, Sgt. Pepper's Lonely Hearts Club Band.