The normally reclusive Allen spoke for about five minutes, one of his longest public speeches, to welcome a crowd of several hundred at the grand opening Friday outside the colorful, freeform walls of the Frank Gehry-designed building.

As artist Chihuly watched and laughed, Allen lifted the glass replica of an electric guitar and hurled it to the podium where it shattered.

“Let the experience begin!” Allen shouted into the microphone as confetti and streamers flew in the background.

“This has been a long process, over eight years,” Allen said afterward. “I’m on a natural high right now.”

Allen, a musician since childhood, originally conceived of the museum as homage to his idol, guitar legend Jimi Hendrix. As co-founder of Microsoft Corp. with Bill Gates,

Allen has the money, an estimated $28 billion, to make his dreams come true. The museum’s scope has since expanded to cover all of pop music, from soul to country, hip-hop to techno-rock.

Allen turned over the running of Microsoft to Gates years ago when he was diagnosed with cancer, an illness he later beat. Since then, in addition to investing in dozens of high-tech, cable, entertainment and other businesses, Allen runs a string of charities and indulges his tastes for rock ‘n’ roll, jet airplanes, yachts, pro sports teams and enjoying himself.

In a brief interview Thursday, Allen mused that he might have spent his own life making music if he and Gates hadn’t started Microsoft.

“Technology sort of sidetracked me,” Allen said, speaking with his sister, Jody Patton, EMP’s director.

“Our family’s always had a passion for reading and books and music,” said Allen, who plays rhythm guitar and occasionally sings lead with his band “Grown Men.”

“I was making music back in high school,” he said, almost wistful. “I have no idea how successful I would have been as a musician, but it’s been a big part of my life all these years.”

The museum, a unique hands-on blend of artifacts, video arcade, nightclub, music class and amusement park, is opening with a three-day bash featuring dozens of performers from across the popular music spectrum, including James Brown, Beck, Eminem and Alanis Morissette.

Its goal is to illuminate the path of creativity, perhaps provide touchstones for emerging talent, Allen said.

“When people realize what it is, as it evolves, it’s going to be a pretty spectacular thing,” said Frank Gehry, the world renowned architect who designed the curvy, colorful building and was here to attend the private EMP gala Thursday and grand opening Friday.

“We haven’t seen anything like this,” he said. “It’s a model for how to reawaken the arts for young people.” The building reflects the energetic mix inside.

Gehry’s table-top model was wonderful, Allen said, but now , “the enormity of it! To see it at that scale, it’s so much more wonderful.”

“I think we challenged Frank,” he said. “I used to use the word ‘swoopy’ with Frank … I wanted him to go more in a curved, exuberant, organic direction, which I think he did in spades with this building.”

Patton said her favorite feature is a flowing, shiny, silver wall, seamless as mercury, between the museum lobby and the towering Sky Church gathering place.

“When the lights are on across the way at the Fun Forest (part of the Seattle Center amusement park tucked next to EMP below the Space Needle)`when the rides are going, you get this kaleidoscope of life,” she said. Gehry worked on the Pacific Science Center built for the Seattle World’s Fair in 1962, but had no inkling then where his creative vision would bring him back to the fairgrounds at the century’s end.

“I knew I was going to make buildings and I hoped somebody would hire me,” he said.

The Los Angeles-based architect dismissed reports that he doesn’t like rock and roll.

“Some of my best friends are rock-and-roll people. It’s just my age,” said Gehry, 71. “I wasn’t in sync with it. It was a circumstance of time.”

Allen and his sister say she’s the one who insisted on Gehry for EMP.

And they say there’ll be more projects. Allen owns considerable downtown Seattle property and has already changed the city’s profile with EMP, the stadium for his Seattle Seahawks and an ongoing remodel of Union Station.

“Our projects tend to be … single focus,” Allen said, to have a theme. The idea is to provide a sense of community or a life-changing experience.

With EMP, they aspired to create “a venue that would appeal to all the people who come to Seattle,” Patton said.

“And people of course now log onto our Website from anywhere in the world. So from that point of view it’s already an international destination.”