Hedy Lamarr wasn't just a beautiful movie star. According to a new play, Frequency Hopping, she was also a shrewd inventor who devised a signal technology that millions of people use every day.

Lamarr—born Hedwig Eva Maria Kiesler in Austria in 1914—developed a passion for helping the U.S. military after walking away from an unhappy marriage to an Austrian Fascist weapons manufacturer in 1937. In an attempt to stall her acting career, he had brought her to his business meetings, where she found herself continuously listening to "fat bastards argue antiaircraft this, vacuum tube that," explains Lamarr's character—played by Erica Newhouse—in the play, Frequency Hopping. In the meetings, they had talked about developing detection devices to listen to, and jam, the radio signals that American aircraft and weapons used to communicate with one another; and Lamarr wanted to foil their plans. "Can you guide your torpedo towards an enemy target—or just use radio control period—without being detected? Or jammed?" Lamarr's character asks.

Lamarr realized that by transmitting radio signals along rapidly changing, or "hopping," frequencies, American radio-guided weapons would be far more resilient to detection and jamming. The sequence of frequencies would be known by both the transmitter and receiver ahead of time, but to the German detectors their message would seem like gibberish. "No jammer could detect it, no German code-breaker could decipher a completely random code," she says in the play.

In 1940 after working on the project for several years, Lamarr called on an unlikely invention partner: avant-garde composer George Antheil, 13 years her senior. As the play—which includes a 25-piece robotic orchestra performing one of Antheil's most renowned pieces—makes clear, frequency hopping spread spectrum is based on a musical concept. The frequencies are "carried in waves through space like melodies," Lamarr's character explains.

More broadly, frequency hopping can be compared with aspects of human communication, argues the production's Brooklyn-based playwright and director Elyse Singer, whose other works include Love In The Void (alt.fan.c-love), a play about Courtney Love's Internet postings. Just as the frequencies "hop" to avoid detection, "we send secret codes to each other, shift and hop and avoid, especially in romantic relationships," Singer says. The play explores this theme in the tumultuous relationship that develops between Lamarr and Antheil.

The pair succeeded in patenting their technology, and presented the concept to the National Inventors Council in 1940, but their invention—which used a piano roll to change between 88 frequencies—was not well received. "The U.S. Navy said, 'Thank you very much for the patent, Miss Lamarr—we won't be needing your services here in Washington,'" Lamarr's character laments onstage.

The technology, says Singer, was far ahead of its time. Although her ideas were at first ignored, the technology (which she and Antheil patented in 1942) was later used by the military—during the Cuban missile crisis in October 1962, for example—and more recently, it has been employed in wireless technologies like cell phones. It was eventually recognized in 1997, when the Electronic Frontier Foundation honored Lamarr with a special Pioneer Award and she became the first woman to receive the Invention Convention's BULBIE Gnass Spirit of Achievement Award.

Fittingly, Frequency Hopping is itself a highly technological production. In addition to the 25-piece robotic orchestra developed by the League of Electronic Musical Urban Robots, the play uses a number of special effects. Singer wanted to portray "surrealist-inspired dreams and fantasies," such as objects popping out of bodies, so she incorporated two screens onto the set—one in front of the actors and one behind them. The front screen is transparent, so the actors can perform behind it; Singer explains that it utilizes a special invisible polymer that reflects projected or solid images so that they appear in three dimensions, like holograms.

Singer hopes that these images, which are used to suggest what the characters are thinking, will help the audience peer into their minds. "Being able to project images on two planes helps us to get into Lamarr and Antheil's mindscape, which is really where artists and scientists develop new ideas," she says.

Frequency Hopping runs until June 29 at New York City's 3LD Art & Technology Center. Tickets are $20 and can be purchased by calling 212-352-3101 or visiting www.frequencyhopping.net