Pearl Jam gathered with an all-star cast of musicians and 28,000 fans in East Troy, Wis., for a weekend of music and fellowship marking 20 years in the music business.

PJ20 was many things to many people. A thank you. A reunion. And, for those keeping track, the only two United States shows that Pearl Jam — Seattle’s musical gift to the world — will do this year.

More than anything, though, the band’s two-day anniversary event at Alpine Valley Music Theater in East Troy, Wis., last weekend felt like one of those family celebrations where a relative stands, raises a glass and toasts the early days, the time since, and the days yet to come.

There was a stage instead of a table. Songs instead of toasts. And a crowd of 28,000 that braved pouring rain and long lines just to watch, listen, and celebrate the community it has become.

“It’s been great,” said Pearl Jam drummer Matt Cameron. “It’s amazing that we still have legs and staying power. But I guess this proves it.”

Pearl Jam picked Wisconsin not just because it is near the center of the country, but because it served as a pristine getaway to spend time with old friends who had been there since early on; new friends it wants fans to know better; and those who seem poised to receive the rock-band baton.

A wet welcome

Saturday started wet and cold, but fans didn’t seem to care, donning ponchos, garbage bags and commemorative sweatshirts, or hanging in the Expo Center, where poster artists like the Ames Bros. and Brad Klausen were selling and signing their wares and greeting fans.

The highlight of the Expo Center was the Pearl Jam Museum, a dizzying collection of artifacts from the band’s trip so far; everything from European subway posters to Jeff Ament’s signature hats to clothes that were torn off frontman Eddie Vedder’s body in the mosh pit. The lines to get in were three hours long.

There was a stencil still used on Pearl Jam’s equipment, a sample of every piece of vinyl ever put out and — perhaps best of all — the original, towering letters from the front of Pearl Jam’s debut album, “Ten.” Fans could stand in front of them, copying the band’s iconic, hands-together pose, and ask security guards to snap them for posterity.

During the day, bands hand-picked by Pearl Jam alternated between two stages set up the hill from the main amphitheater.

The Young Evils from Seattle got each day started with noontime sets, followed by alt-rock Star Anna and The Laughing Dogs, Jason Lytle, David Garza, Thenewno2 (fronted by Dhani Harrison, son of George), Joseph Arthur, Liam Finn, Glen Hansard and John Doe, who closed out those stages at 5:30..

At 6 p.m., Mudhoney opened the mainstage, Mark Arm leading his roof-blasting, mosh-inducing band through powerful sets that included grunge standards like “Touch Me I’m Sick.”

They were followed each night by The Queens of the Stone Age, The Strokes (Vedder popped on to duet with Julian Casablancas on “Juiceboxxx”), and then Pearl Jam, which played three-hour shows, each with their own diverse set list. Saturday night included rarities like “Push Me, Pull Me,” and “In the Moonlight,” for which Queens frontman Josh Homme joined Vedder on vocals.

Soundgarden frontman Chris Cornell joined Pearl Jam halfway through each night’s set for a Mother Love Bone/Temple of the Dog reunion, which included beloved songs like “Hunger Strike,” “Say Hello 2 Heaven” “Call Me a Dog” and “Reach Down.”

And there was this: an acknowledgment of the late Andrew Wood, lead singer of Malfunkshun and Mother Love Bone, who died of a heroin overdose in 1990.

“It was a turning point in my life … and I think everybody here’s lives when we lost him,” Cornell said.

A brighter day

On Sunday, the sun brought the band members out early onto others’ stages.

Pearl Jam bassist Jeff Ament, drummer Matt Cameron and lead guitarist Mike McCready joined Joseph Arthur for his “In the Sun,” and a new Ament song called “When the Fire Burns.”

Vedder, in shorts and sunglasses and carrying an iced coffee, joined Finn on drums for his set, Hansard for a riveting duet on his Academy Award-winning song, “Falling Slowly” (something they did throughout Vedder’s recent “Ukelele Songs” tour) and Doe for “Golden State.”

That night, during an energized, seemingly greatest-hits set, Vedder spoke to the crowd about his passions, both personal and political.

He thanked those who had joined him in supporting the West Memphis Three, who were released from prison Aug. 19 after DNA testing could not connect them to the 1993 murder of three boys in Arkansas. Vedder and others had held fundraisers and lobbied for the men.

“Thanks for trusting us,” Vedder told the crowd. “And if you didn’t trust us on that … You should have known better.”

He also used the anniversary to acknowledge those who had helped the band reach this place and time.

Longtime producer Brendan O’Brien. Drummer Matt Cameron, the band’s third, “for keeping the band alive.” Keyboardist Boom Gasper. And Neil Young, who Vedder met 19 years ago at a tribute to Bob Dylan.

“We didn’t know back then we were going to be adopted by him,” Vedder said. “He got us through some tough times.”

He thanked the band’s crew: “They were with us in the tiny clubs. They’re all our family.”

And Vedder thanked the women in their lives.

“Everybody, every member of this group has a very powerful woman next to us, behind us and in front of us,” he said. “So to all the women — we have just one each — in our lives, we just want to thank all the mamas and wives and girlfriends back home. We love you.

“Thanks for letting us have a night out.”

It seemed impossible to capture it all — the years, the relationships, the music, the tours, and the accomplishment of staying together for 20 years — but Vedder tried on Sunday night, when he played a song he had written just hours before, alone and acoustically.

” … Couldn’t have told me back then that it would someday be allowed to be so in love with life, as deeply as we are now,” he sang, as the crowd cheered. “Never thought we would. Never thought we could. I’m glad we made it. I’m so glad we made it. I’m so glad we made it ’til when it all got good.”

With that, and whether they held a cup or not, the crowd raised its hands to toast.

Nicole Brodeur: 206-464-2334 or nbrodeur@seattletimes.com.