Of all the weird scenes that populate seventies science-fiction cinema, the most bizarre might be in 1971’s The Omega Man. Based on Richard Matheson’s I Am Legend, the film imagines a world in which fallout from a distant war has eradicated most of humanity, turning survivors not into vampires (per Matheson) but feral albino Luddites.

But the strangeness occurs before we even know this much. Robert Neville (Charlton Heston) careens through the city’s bright and desolate streets, an easy-listening eight-track playing in his red convertible, only to stop in front of a movie theater. On the marquee is Woodstock, the 1970 film of the 1969 concert, a quintessential sixties event.

“Great show,” he remarks to no one. You might expect Neville to riddle the theater with his assault rifle, just as he did moments before, shooting at a ghoulish silhouette in a window. (You also might expect it based on Heston’s later incarnation as president of the NRA.) Instead he gets the projector running and takes a seat, and suddenly . . . we’re watching Woodstock.

Country Joe and the Fish announce their brand of “rock and soul music.” Neville grimaces, hand on the barrel of his gun, as a hippie raves about his recently elevated consciousness: “This is really beautiful . . . just to really realize what’s really important,” he rambles. “The fact that if we can’t all live together and be happy, if you have to be afraid to walk out in the street, if you have to be afraid to smile at somebody, right, what, what kind of a way is that to go through this life?”

The gun stays put. As the hippie speaks, Neville mouths the words along with him. We realize he’s done this lonely ritual many times before.

“Yup,” he concludes, “they sure don’t make pictures like that anymore.”