The run-up to the "Michael Forever" concert was overshadowed by the Los Angeles manslaughter trial of Jackson’s doctor, and marred by fan criticism, sluggish ticket sales and dissension within the Jackson family. But once the four-hour show started, Jackson’s musical genius, and the warm tributes of friends and family, carried the night.

"We’re very happy to be here on this special night to honor our father," said Jackson’s 13-year-old daughter Paris, who made a brief onstage appearance alongside brothers Prince, 14, and 9-year-old Michael Joseph Jr., known as Blanket.

The children wore outfits evoking their father’s famous styles — Paris most strikingly, in a red and black "Thriller"-style jacket. Blanket stood stoic and shy, but the older children smiled and appeared confident in the spotlight.

On a stage shaped like a giant glove, musicians including Christina Aguilera, Gladys Knight and Cee Lo Green performed songs from across Jackson’s career — from his childhood with the Jackson 5 through monster solo albums like "Thriller" and "Bad."

The Black Eyed Peas, probably the biggest act on the bill, pulled out of the lineup this week, citing "unavoidable circumstances."

Participants urged fans to ignore the criticism and controversy, and to revel in the celebration of Jackson’s musical legacy.

"It’s not about the controversy," said R&B star Ne-Yo, who kicked off the show with a rendition of "Billie Jean," complete with some passable moonwalking. "It’s not about the trial. It’s not about his death. It’s about celebrating his life. It’s about celebrating his music."

The 50,000-strong crowd at Cardiff’s Millennium Stadium did just that, roaring with approval as Jackson’s brothers Marlon, Tito and Jackie — three-fifths of the original Jackson 5 — took the stage to perform "Blame It On the Boogie" with British boyband JLS.

"Can you feel his spirit in the house tonight?" asked Marlon. Judging by the cheers, the fedora hats and the sequined gloves in the audience, many could.

Jackson died in June 2009, at age 50, as he was preparing for a string of comeback concerts in London.

His last hours are being relived in graphic detail at the manslaughter trial of Dr. Conrad Murray, accused of giving Jackson a lethal dose of the anesthetic propofol and other sedatives in the bedroom of his rented mansion on June 25, 2009.

"This is a great counter-act to that," said Motown great Smokey Robinson, who gave a soulful rendition of "She’s Out of My Life." ”And it gives people something happy to do, rather than thinking about what’s going on in the trial."

The show mined a rich trove of Jackson hits. Leona Lewis crooned "I’ll Be There," Beyonce delivered the early single "I Wanna Be Where You Are" and Jamie Foxx performed "Rock With You." Aguilera sang Charlie Chaplin’s "Smile" — one of Jackson’s favorite songs.

"Tonight is a history lesson," Foxx told the crowd. "We’re going to cover five decades of greatness."

The show reached a climax with Knight performing the poignant "Gone Too Soon" before a rousing finale that brought most of the performers — and the Jackson children — back onstage for the exuberant "Don’t Stop Til’ You Get Enough."

The concert has divided the King of Pop’s family and followers. The three brothers, sister La Toya and vocal group 3T — composed of three of Michael’s nephews — all performed, while 81-year-old matriarch Katherine was in the audience.

But Michael’s brothers Jermaine and Randy and sister Janet have stayed away, saying it is wrong to hold the show at the same time as Murray’s trial.

Before the show, Marlon Jackson said he respected his siblings’ decision, but said he was sure Michael would have approved.

"Each one of us grieves differently," he said. "We want to celebrate the positive side of his life, the positive things that he did."

Some fan groups around also criticized the show for ticket prices that started at about $100 and for what some regard as an out-of-the-way location in Cardiff, 150 miles (240 kilometers) west of London.

"I believe it should wait, not only because of the Murray trial," said Wesley Noorhoff, president of a Dutch Michael Jackson fan club. "If you do a tribute to Michael, it has to be the best there is, just like Michael."

But those who came to Cardiff said it was a fitting antidote to the grim courtroom spectacle in Los Angeles.

"There’s a lot of negativity in that courtroom," said Ronnie Lee, a 32-year-old truck driver from Pembroke, Wales, sporting a "Thriller" T-shirt. "This is a chance to say, ‘Thank you Michael’ and celebrate the music."

As the crowd poured out of the stadium, opinion was divided.

"Rubbish," said Sophie Stockdale, 23. "If you wanted to watch Beyonce on video link, you could do it on YouTube."

But Sophie Morris, also 23, said she’d loved it.

"It was amazing," she said. "I actually cried three or four times."