Believe it or not, there was once a time when the city wasn’t full of gum-smeared, multi-screen movie theaters; the semi-creepy Movie Fone guy didn’t tell you to “press 2” to find your flick; and climactic love and death scenes weren’t interrupted by cell-phone rings playing Usher’s latest hit.

Those good ol’ days are celebrated in the new documentary Before the Curtain Rises, which will be partially screened today at a gala event at the River Oaks Theatre. The film traces the history of Interstate Theatres, a Texas motion picture exhibition dynasty created during the Roaring Twenties. At one time, Interstate operated 250 movie palaces, replete with assigned seating, ushers and balconies. There were even nurseries (imagine!) and “crying rooms,” where affected folks could steal away from weepy dramas. In short, the palaces were tailored to making moviegoing an easy, pleasurable experience for everyone. (As opposed to these days, when theaters are tailored to 14-year-olds who wanna make out.) So what happened to Interstate Theatres? The regal chain collapsed in the ยด70s with the death of the studio system. But a few remain: Interstate’s last palace theater, The Plaza in El Paso, was recently reborn thanks to efforts by locals, and there’s our venerable River Oaks here in Houston. But these spots are nearly extinct, something that Before the Curtain Rises points out all too clearly.

“There’s a lot of anxiety in the movie industry today,” says Jeffrey Mills, who was inspired to produce and direct Curtain after discovering that his dad had worked at an Interstate theater as a boy. “They want to get people back into theaters, but the experience just isn’t pleasurable. People can get their movies at home and, soon, on their phones,” says Mills. “So maybe the industry should take a lesson from these Interstate showmen, who understood that the theater experience was just as important as the film.” Mills and the Documentary Alliance are creating quite an experience for attendees of today’s screening. After a short preview of the film, Variety reviewer Joe Leydon will moderate a discussion of the future of the motion picture exhibition business. Then, it’s a gala party.

Fun stuff, but Mills wants people to understand that the theme of his film is about more than looking back. “It’s not just nostalgia,” he says. “This could be the difference between the theaters going away, or the theaters staying.”

Thu., April 6, 7 p.m.