LOS ANGELES — They came dressed as Pink Ladies and Beauty School Dropouts. They cheered Danny Zuko at Thunder Road. The rama-lama ding-donging? Deafening.

No, this wasn’t a karaoke club. It was the premiere here for "Grease: Sing-A-Long," a rerelease of the 1978 musical starring John Travolta and Olivia Newton-John. By adding lyric subtitles, Paramount Pictures hopes to inspire audiences in places like Texas and Michigan — clad in costume, preferably — to trek to multiplexes and sing about summer lovin’.

"The goal is to create a true event," said Adam Goodman, president of the Paramount Film Group. "How do you get groups of young people going to the movies and having a great time?"

The key term is "young." Older moviegoers may still prefer to sit in silence, but younger audiences — the ones studios work hardest to motivate off the sofa — are increasingly programmed to interact and multitask. Sitting quietly in a theater starts to feel like a drag when you can watch the DVD at home while texting a friend, playing a video game and posting witty comments on Facebook.

Despite 3-D blockbusters like "Avatar" and "Alice in Wonderland," moviegoing in North America is in trouble. For the summer period, which typically accounts for 40 percent of annual box office receipts, attendance is down by about 3 percent, to 309 million tickets, compared with a year earlier. Years of sharp ticket price increases have papered over the problem — revenue for the summer is up about 4 percent — but movie studios and exhibitors are now starting to fear a consumer pushback.

Since at least "The Rocky Horror Picture Show," moviegoers have created their own events around films — wearing costumes, bringing props, singing along and generally treating the theater as though it’s their own den. Now it is the multiplex chains and film studios that are trying to manufacture audience participation as a way of coaxing a certain crowd into theaters. Just bring your friends, they say, and buy a lot of candy.

The strategy depends on creating an excitement that was once organic, and it could easily backfire, said Matt Britton, the managing partner of Mr Youth, a New York social marketing agency. "You don’t want to force a cultural habit on people, especially young people who are very savvy about being manipulated by marketers," he said. "But it’s definitely savvy to try and make the moviegoing experience less linear and more interactive."

There are signs, at least in the short term, that audiences are responding. The "Grease: Sing-A-Long," which features some minor lyrical changes to the make songs less crude, opened on Thursday in limited national release and has been selling out in cities in California, New York, Texas and Florida.

Arriving at a Los Angeles screening, Inthia Seabrooks paid homage to the movie’s "Beauty School Dropout" number by dressing in a silver smock and wearing a headdress made out of an empty KFC bucket. "If you’re going to get all dolled up and go out to the movies, they had better offer you something special," said Seabrooks, 28. "This is special."

In addition to signing on for "Grease: Sing-A-Long," which at the very least is a way for Paramount to keep milking a 32-year-old cash cow, AMC Entertainment has been busy hosting participatory "Twilight Saga" marathons. AMC, one of the largest theater chains in North America, handed out collectible lanyards at the $30 triple feature and encouraged customers to root for their favorite lead character by wearing T-shirts emblazoned with "Team Edward" or "Team Jacob."

"Everyone together laughing or crying or cheering — that’s why you go to the movies, and we want to really reinvigorate that experience," said Sun Dee Larson, AMC’s vice president for film and product marketing.

For Walt Disney Studios, all of this multiplex festivity leads back to one thing: Chihuahuas. To promote "Beverly Hills Chihuahua," released in fall 2008, Disney invited Chihuahua owners to bring their dogs to a series of screenings. The goal was to attract a few dozen people, but hundreds turned out — many with their dogs dressed in outfits, like tiny little tuxedos.

Pictures from the event became a hit on the Web, helping to turn the movie into a success. The lesson for movie marketers was in the Twitter age, you can easily convince people that moviegoing is a party with a simple promotional event.

So Disney, aiming to create a group-fun vibe around "Alice in Wonderland" last spring, staged a similar shindig at a Los Angeles mall. The studio invited MySpace to stream video of the event and told guests to "dress in your best Alice costume." A crop of Mad Hatters and Red Queens showed up and — presto — moviegoers started popping up in similar garb at theaters across the country.

Next up: Elvis. On July 29, National CineMedia will present a compilation of concert footage called "Elvis on Tour: 75th Anniversary Celebration" in more than 450 theaters. "I’m sure Elvis fans will arrive in full costume," said Michelle Portillo, a National CineMedia spokeswoman. "We receive several calls from Elvis impersonators about it a day."

National CineMedia also organizes multiplex sing-alongs ("Forever Plaid") and simulcasts sporting events (patrons dress in team colors and cheer as if they were in a stadium).

Feeling bashful about behaving this way in a theater? To encourage reluctant singers, Paramount layered a recorded audience’s voice — like a sitcom laugh track — into the musical numbers in its new "Grease."

But beer helps, too. Dale Hurst, marketing director for Carmike Cinemas, said his chain hired caterers with mobile liquor licenses to service theaters for these kinds of events. "Some people really let loose," he said.

Betty Henderson, 67, acknowledges that it took her awhile to warm up to the idea of singing during a movie. "I just thought it sounded a little strange," she said. But before long, Henderson was belting out "Summer Nights" with the best of them.

"The energy of the crowd was so great that it just made you feel good," she said afterward. "I’ve never experienced anything like that."