An article in The Age talks about
the role of pop lyrics in the cultural shift of the "1960s":
For a while they were a very effective form of mass media, communicating notions about authority, sex and drugs to kids around the world. This mattered because other media, such as newspapers, television and films, were still very conservative. Eventually they caught up, but until they did pop lyrics had an importance they have never had before or since.
But others, particularly those about sex, contained messages that were able to be played on radio only because so few people knew what they meant. In some cases, this was because few people paid close attention to the words. In other cases, it was because the words were obscure, at least by the standards of the time. (It was, let's not forget, a period when Ian Fleming could call a woman in one of his bestsellers Pussy Galore.) This meant lyricists could get away with sentiments that were pretty blatant, even by more recent standards.
For the markers of cultural change, I referred to my favourite book on the period, The Sixties, by American academic Arthur Marwick. He likes the idea that the decade was a "mini-renaissance" that actually ran from 1958 to 1974. In the first of those years, the forces that had been building through the 1950s (civil rights, affluence, the extension of adolescence through expanded higher education) accelerated. The latter date is when the end of the West's participation in the Vietnam War and the impact of the oil crisis hit home.