[The Doors'] music was a melodic hard rock which did not detract from Morrison's lyrics. Morrison, when he was good, was very good, using broad, emotional and exotic images to create poetry that urged "breaking free" of traditional restraint, always a hot topic but particularly so in hippie circles in 1967.

Morrison managed to take "breaking free"—the perennial plea of the hip—and turn it into an ambiguous semi-nightmare. In his songs, the characters wanted freedom but feared it, and played out their torment in the company of an assortment of familiar, but at times foreboding images: the sun, the sea, running, falling, sleeping, and snakes—there seemed no end of reptiles in Morrison's songs.

At times, the Doors proposed rock music as a tool to use in breaking free—a notion that was popular in 1967—an extension of the rock 'n' roll song that views rock as...