“I wouldn’t say it’s easy,” retired real estate developer Eli Broad says of raising money for the arts in Los Angeles. “A tradition of philanthropy has to be established in this city. But times are changing.”

Broad himself donated $50 million to build the Broad Contemporary Art Museum on the expanding ­campus of the Los Angeles County Museum of Art. Two years ago, the 74-year-old billionaire recruited longtime friend Nancy Daly Riordan—who recently separated from her husband, former L.A. mayor Richard Riordan—to chair the museum’s executive committee. Riordan then signed up Bobby Kotick, the 43-year-old chairman and C.E.O. of videogame company Activision, and challenged him to try and reel in trustees from his contacts in the entertainment industry. Kotick’s catches: MySpace co-founder Chris DeWolfe, author Michael Crichton, Barbra Streisand, and former Yahoo C.E.O. Terry Semel.

But where are the studio players who so proudly hoard masterpieces in their Brentwood homes?

“It’s always been a mystery to all of us,” says Lacma trustee Robert Maguire III, a developer who says he has often wondered why the city’s most conspicuous industry has largely avoided arts philanthropy. His one-word supposition: “Tight.”