Producer Berry Gordy speaks during the memorial service for Michael Jackson at the Staples Center in Los Angeles, Tuesday, July 7, 2009.

A star-studded public tribute to Michael Jackson was held Tuesday in Los Angeles with thousands of randomly selected fans joining family and friends to bid farewell to the King of Pop.

Just before the memorial service began at Staples Center in downtown Los Angeles, condolence letters from music legend Diana Ross and former South African President Nelson Mandela were read to the crowd.

Ross, who introduced Jackson and his brothers to the entertainment industry in 1960s, wrote that Jackson was "part of the fabric of my life in a way that I can't seem to find words to express."

In his letter, Mandela wrote that "Michael was a giant and a legend in the music industry and we mourn with the millions of fans worldwide."

A church choir opened the memorial service by singing "Soon and Very Soon," as the singer's flower-covered casket was wheeled to the Staples Center stage.

And then singers including Mariah Carey and Loinel Richie began to perform sadly-themed songs like "I will be there" to pay tribute to the late superstar.

Earlier in the morning, hundreds of friends and relatives gathered at the Forest Lawn cemetery in Hollywood Hills to bid a private farewell to Jackson, whose casket was then placed inside a black hearse and driven toward Staples Center for the public memorial.