This moody, rainy-day masterpiece has its roots in a cowboy song. Krieger was messing around with the ominous, minor-key “Ghost Riders in the Sky,” a tune about undead cowpokes popularized by Vaughn Monroe in 1949. Sitting behind his electric piano, Manzarek monkeyed with the changes and jazzed up the feel and they were off to the races. But the idea of a murderous hitchhiker introduced in the second verse went back a long way with Morrison. He had written a screenplay about a homicidal hitchhiker, which was eventually made into an unreleased short film by Morrison and a few friends under the name HWY (for highway). By the time it was done, the hitcher was no longer a killer but merely a wanderer.

On the philosophical side, it’s been suggested by academicians that the verse that ends both the song and the album -- the one that goes “Into this house we’re born / Into this world we’re thrown / Like a dog without a bone / An actor out on loan” -- is straight out of Nietzsche and Heidegger, whose existentialist ideas Morrison was exposed to at least as early as his time at UCLA, and possibly even in his high-school bookworm era. It would be the last recorded statement he’d leave behind.