The Beatles were audibly growing up on 1965's Rubber Soul, aiming higher on both the lyric sheet and in the studio and thinking in terms of making a coherent album rather than just packing two sides of an LP with singles. Their musical palette was expanding, too, with "Norwegian Wood (This Bird Has Flown)" indulging in psychedelic folk and George Harrison's new fascintion with the sitar and stately tunes like "Michelle" and "In My Life" paying greater attention to arrangement and atmosphere. John Lennon referred to Rubber Soul as "the pot album." 

First listen: