The music floating Wednesday from Walt Disney Concert Hall was a concerto of sanding machines, as workers began taking the shine off some of the building's stainless steel panels.
Faced with complaints that the polished-steel parts of the curving exterior created an unbearable glare for nearby residents, passing motorists and pedestrians, a group from Custom Metal Fabricators gently climbed onto the architectural landmark with hand-held sanders.
They looked like normal workers in hardhats and industrial gloves, but their efforts came after much artistic preparation. The firm spent three weeks making eight to 10 different test panels that would show the look of the metal after sanding, said Patrick Keohane, the firm's president. (The vast majority of the exterior is brushed steel, less reflective than the polished steel.)
The samples were judged by architect Frank O. Gehry and his company, who selected the finish.
Gehry's firm settled on one that requires a two-step process. The workers take off the gleam with a rectangular sander, then add a swirling finish with an orbital sander. The idea is to leave the surface with a distinct texture, not a uniform look.
They use 220-grit sandpaper, which provides the desired finish, and wipe off the dust with a soft cotton cloth.
The sanding process makes a major difference. Before, the workers could see their reflections in the mirror-like surface. After sanding, the steel takes on a dull, gray look, like the underside of aluminum foil.
Keohane says that only a fraction of an inch is sanded off and that the process does not compromise any of the structure's famous marine-grade steel, also used on boats and made to resist rust.
Gehry's firm also mapped with pink lines exactly which parts of the shiny surface would be sanded.
"It's going to look slightly like a different element," said Howard Sherman, vice president of the Music Center. "The goal was never to make it look like the rest of the building. It was to solve the problem and maintain artistic integrity."
Workers will sand 4,200 square feet of steel above the Founders Room and, later, the 1,800 square feet on the marquee for the Roy and Edna Disney CalArts Theater, known as REDCAT.
Besides being shinier than the rest of the exterior, those sections also have sharper curves that magnify the sunlight, bouncing it back and forth and into a beam. One concave curve that Sherman called "the elbow" was causing particular problems.
Some residents of the condominiums across Hope Street have complained that, on a sunny day, reflections from the hall drive them from their patios and heat up their rooms.
A consultant hired by the county to investigate the problem also found that the beams had roasted the sidewalk to 140 degrees Fahrenheit, enough to make plastic sag, cause serious sunburn to people standing on the street and create a hazard to drivers.
Officials at the Music Center, the county-funded nonprofit entity that operates Disney Hall, said they responded immediately to the first complaints in June 2003, placing a gray tarp over some of the curves.
"We want to be good neighbors," Sherman said. The Music Center said it had been working with the residents and the architects to find a solution ever since.
The six-week project will cost the Music Center $90,000, officials said. Custom Metal Fabricators will also begin sanding the REDCAT marquee about March 28, when the avant-garde theater has a break in its schedule, said publicist Tamar Fortgang.
REDCAT will see the biggest change, because the undulating steel above the entrance features the outlines of cats that will disappear.
"The cats are going to be sanded off," Fortgang said. "Honestly, you can't see the cats."
The California Institute of the Arts, or CalArts, in Valencia will pay $21,000 for that project, which will take about two weeks.
The effort to accommodate residents has set off a debate about whether it is right to alter the architectural landmark, especially less than 1 1/2 years after the $274-million complex opened.
Officials at Gehry's firm have insisted that they took into account possible glare, but that the curved panels were erected at slightly different angles than called for in their design.
The architectural firm did not return calls or e-mails seeking comment Wednesday.
Passersby stopped Wednesday to look at the workers, two of whom where kneeling at the base of the Founders Room as they buffed. One man was suspended on a rope strung from a hook atop the room, in a system regularly used by Music Center employees to clean the building with a squeegee.
Pat Lentz admired the partially sanded structure as she toured Disney Hall with a friend. They were both snapping pictures.
"It's nice with the satin finish," said the 67-year-old Seal Beach resident. "I think it enhances it. You can see the shapes and you're not distracted by the glare."
Minna Cluster and Gloria Chang, who work at the nearby Department of Water and Power building and regularly walk by Disney Hall around lunchtime, said they were happy that someone was dulling the glare.
"We have to wear sunglasses," Chang said, as she put her hand between the glinting panels and her eyes.
But Cluster wasn't too impressed with the sanding.
"It's too bad they have to cover up the beautiful steel," she said. "Maybe they can put some color on it to make it look better."
Mary Cornelison, 52, said she walked by the building every day on her way to work at the DWP. She said the building generated some heat, but that it wasn't terrible.
"They should've opted to put film on everybody's window there," she said, pointing to the condo complex. "This other way, they have to change everything. It doesn't look right. There was balance with the building. I think the artist wanted contrast."