After more than 75 years in the shadow of its glamorous cousin, San Francisco's "other" bridge is getting a chance to shine. The San Francisco-Oakland Bay Bridge has been turned into the latest — and by far the biggest — backdrop for New York artist Leo Villareal, who has individually programmed 25,000 white lights spaced a foot apart on 300 of the span's vertical cables to create what is being billed as the world's largest illuminated sculpture.

Villareal, 46, whose previous installations have included an underground walkway at the National Gallery of Art and the Bleecker Street subway station in Manhattan, is scheduled to flip the switch on "The Bay Lights" with a click of his laptop computer on Tuesday at 9 p.m. Donors attending a private waterfront reception will see it set to music, but the work, which uses sequences of shifting light to produce an almost-infinite array of abstract patterns, will be visible to anyone with a view of the western half of the bridge for at least the next two years. "People are attracted to light and they will respond in a variety of ways, even if they don't know anything about art, programming or technology," he said one evening late last month while fine-tuning the shimmering display from a pier next to San Francisco's Ferry Building. "It's really a wonderful piece of public art."

For Ben Davis, a San Francisco public relations and communications professional who conceived of the idea of turning the busy Bay Bridge into a 1.8-mile-long canvas, the $8 million project represents a long-overdue celebration of a conduit that has been eclipsed by the Golden Gate Bridge almost from the time its concrete set. It opened to great acclaim in November 1936 — at the time it was the world's longest and most expensive bridge — but lost the limelight with the opening of the majestic Golden Gate five months later. "Those bridges are sort of like twins, one very beautiful, one very hard-working," said Davis, whose interest in the Bay Bridge was sparked by his firm's work promoting the soon-to-be-completed rebuilding of the bridge's earthquake-damaged eastern span. "For 75 years, the Bay Bridge has had this pleasure of being able to see the Golden Gate Bridge. Now, we are giving its sister something really beautiful to look at for a while."

Villareal, who studied sculpture at Yale and completed a graduate program in interactive telecommunications at New York University's Tisch School of the Arts, "Bay Lights" has represented a sort of homecoming. After graduate school, he spent three years at Interval Research, a Silicon Valley think tank spearheaded by Microsoft cofounder Paul Allen. But it was at Burning Man, the annual art and music festival in Nevada's Black Rock Desert, that the artist found his medium. In 1997, he built a light sculpture as homecoming beacon for his tribe's camp site. In the years since, his creations have been featured in galleries and museums around the world, although he still sits on the festival's board and attends every summer. "People focus a lot on the lights, but in a way the most interesting thing about his work is that it's really dealing with algorithms, it's really about emerging software, unpredictable software," said Steven Johnson, author of "Where Good Ideas Come From: The Natural History of Innovation" and a longtime friend of Villareal's. "Because of technology and software really being so central to the Bay Area, to have its great epic urban art project be fundamentally all about code, it's just pretty a much a marriage made in heaven."

Like many artists, Villareal is hesitant to delve too deeply into his creative process, preferring to let his audiences draw their own conclusions. He said he drew inspiration from the bridge's surroundings, such as the bay waters that flow under it and the birds that soar above it, as well as from mathematical formulas and physics principles. The finished product, he said, is something like the song-shuffling program on a mp3 player, only the "songs" — his light sequences — do not begin and end at the same point every time. "It's been very painterly, really, a process of adding light and taking it away," he said. "My goal is for people not to worry about what they missed, but to really be with it and experience it."

Spectators who have seen Villareal working on the lights with his laptop in recent months already have been inspired to set their brief previews to music and post the results on YouTube. "Bay Lights" is scheduled to be exhibited from dusk until 2 a.m. until March 2015. Organizers say they have raised $6 million of the $8 million for the project from private funding sources. To raise money to keep the lights on, Davis has created a program that allows people to sponsor or name a light for $50 each. One family bought a series of them in honor of a relative who had worked as an engineer on the bridge for 15 years.