The pop star himself, who has not appeared in public since his 14-week trial ended Monday, was nowhere in sight.
Among the approximately 400 people who arrived at the Chumash Indian Casino was juror Pauline Coccoz. When she walked into the casino and heard Jackson's music playing, Coccoz said, the enormity of what had transpired hit her.
"They were playing 'Beat It,' and I almost started to cry," she said as she waited to enter the showroom. She said that earlier in the day, she had received a wristband needed for admission to the party.
The crowd erupted in cheers as Jackson's mother, Katherine, arrived to the sounds of the song "I'll Be There." She came on stage at the end of the show to thank her son's fans from around the world for their support.
"We couldn't have done it without you," Katherine Jackson said as her son Tito stood next to her, his hand on her shoulder.
Others spotted arriving for the show included defense attorney Robert Sanger and Jackson's magician friend, who calls himself Majestic Magnificent.
Reporters were kept out of the showroom, and an Associated Press reporter who got inside briefly was escorted out by tribal police. Casino officials said they had orders from the Jackson family to keep journalists out.
Tito Jackson has been performing periodically at the casino, and he had been scheduled to appear Friday night before it was decided to turn the show into what one of his band members called a celebration of thanks.
Coccoz said that when someone gave her the wristbands she decided to bring her family, partly as a public display of her confidence in the jury's verdict.
On Thursday, Superior Court Judge Rodney S. Melville, who placed a tight lid of secrecy on evidence in Jackson's trial, said he intends to release virtually every sealed document and also ordered that authorities return the pop star's passport.