Late in 2003, Silicon Valley investor Roger McNamee got a phone call from rock star Bono with a proposal. The U2 lead singer, who had previously sought business advice from McNamee, had an idea for investing in the entertainment industry.

"Bono had a big idea but needed a partner," McNamee said. "A mutual friend reminded Bono that he knew me."

Less than a year later, Elevation Partners L.P. was born. The Menlo Park, Calif., private-equity firm includes Bono, whose real name is Paul Hewson, and McNamee as managing directors. It raised almost $1.9 billion from more than 50 pension funds, institutions, college endowments and individuals for its first fund, which began investing in 2005.

Elevation, which is named after a U2 song, is looking at media and entertainment companies that are in a position to benefit from technology, said McNamee, a former technology stock analyst turned venture capitalist.

"I look for places where technology is disrupting the status quo," McNamee said in an interview in a conference room furnished with a video-arcade game machine.

Spending by consumers and businesses on online access, online content and advertising will increase 14.5 percent to $74 billion by 2009 from 2004, estimates Veronis Suhler Stevenson L.L.C., a private-equity media investment firm in New York. For its first fund, Elevation aims to acquire stakes in eight to 12 music, video-game and print-media companies, ranging from $50 million to $300 million.

So far, Elevation has made three investments. In November 2005, the firm set up a holding company with $300 million of capital for its video-game companies, including a stake in BioWare Corp. and Pandemic Studios L.L.C., creators of Baldur's Gate, Mercenaries and Star Wars games.

The same month, the partners bought 14 percent of online real estate agent Homestore Inc. for $100 million. (The company has since changed its name to Move Inc.)

In August, Elevation bought an undisclosed minority stake in Forbes Inc., owner of 90-year-old Forbes magazine and Forbes.com.

NcNamee brushed off suggestions that a flamboyant rock star such as Bono makes an unlikely partner for Steve Forbes, a former Republican presidential candidate.

"In the end, we are going to be judged on whether we make a difference or not," he said. "We want to let our investments speak for themselves."

McNamee has a knack for finding good investments in unpopular industries, said Kim Polese, chief executive officer of software company SpikeSource.com in Redwood City, Calif. "He's a maverick," Polese said.

McNamee, whose shaggy brown hair grazes his shoulders, began his investment career in 1982, when he joined T. Rowe Price as a defense electronics and software analyst after earning an M.B.A. at the Tuck School of Business at Dartmouth College.

While McNamee was building his investing resume in a series of venture-capital firms, he also had a second career: as a rock musician. The self-taught guitarist is the lead singer of the Flying Other Brothers - a band formed with his younger brother, Giles. Other band members include Pete Sears, a former member of Jefferson Starship.

Playing with the Flying Other Brothers enabled McNamee to meet other people in the music world. Once a week, he advised the surviving members of the Grateful Dead - Bob Weir, Mickey Hart, Phil Lesh and Bill Kreutzmann - on their investments.

McNamee says he built a plan - called Bandwagon - for the Dead that was intended to allow the rock legends and other bands to sell their music, concert tickets and T-shirts directly to fans.

U2, one of the few rock bands to own rights to its own music, also became interested in the project. In February 2001, Bono and U2 lead guitarist The Edge, whose real name is David Evans, met McNamee in Los Angeles to discuss the project.

"At this meeting, I became impressed with the business savvy of Bono and Edge," McNamee said.

The Bandwagon project never got off the ground because the Dead decided to sell its music and other paraphernalia through another company.

Two years later, Bono and McNamee came together again to craft the investment plan for Elevation Partners in Dublin and New York. By May 2005, they had raised $1.9 billion.

Elevation has the right mix of talent, said Paul Kedrosky, a venture partner at Vancouver-based Ventures West. "It's not all bankers doing deals based on balance sheets," he said.