It was a slow winter day, and I had just left the Anthology Film Archives in New York after a screening of “Andy Warhol’s Frankenstein.” It had seemed like a long afternoon, what with the beheadings and the orgies and whatnot. Curiously, Baron von Frankenstein insisted on calling his creature’s nose its “nasum.” Also, he observed that “in order to know death, you have to” — let’s paraphrase here — “know life in the gallbladder.”

I stood there on Second Avenue, more than a little discombobulated.

And then, from an open window, I heard Jerry Garcia singing, like the voice of an old friend. “Dry your eyes on the wind,” he sang.

Garcia’s mother took him to see “Abbott and Costello Meet Frankenstein” when he was 6 years old, he once said in an interview. “My father had just died the previous year. That was my first sense that there are things in this world that are really weird, and there are people who are concerned with them. I think that sounds like fun.”

It was fun. And it was 50 years ago today — Feb. 27, 1969 — that Garcia and the Grateful Dead stood onstage at the Fillmore West and recorded the live version of “Dark Star,” a song that is still about as fun, and as weird, as American rock ’n’ roll can be.