"Michael Forever" is going ahead despite a series of setbacks, including squabbling in the Jackson clan, angry fans and a major headline act pulling out at the last moment.
"It's going to be a huge and spectacular event," said Chris Hunt, head of Global Live Events, which is staging the show for up to 50,000 fans.
In a sign of the difficulties he has faced putting the tribute together and promoting it, 10,000 tickets were still unsold in the days before the gig.
Among the acts taking part will be Jackson's brothers Marlon, Tito and Jackie and his sister La
Toya, who will be performing live in public for the first time in nearly 20 years.
Also expected are his mother Katherine, three children and several other close family members.
But brothers Jermaine and Randy have criticized the concert, because it coincides with the involuntary manslaughter trial in Los Angeles of Jackson's doctor. Janet Jackson has declined to take part citing the same reason.
"Thriller" singer Michael, one of the most successful yet troubled artists of the pop era, died in 2009 aged 50 while rehearsing for a series of comeback concerts.
"BEST THERE IS"
In addition to the Jacksons, the lineup includes Christina Aguilera, Cee Lo Green, Jamie Foxx, Gladys Knight and Smokey Robinson, and among British stars appearing will be Leona Lewis, Alexandra Burke, JLS and Diversity.
Beyonce will appear in a video performance but Black Eyed Peas, originally confirmed to attend, pulled out earlier this week without explanation.
Some fan clubs have also protested against organizers, questioning the timing of the gig and confusion over charitable donations.
Hunt told Reuters earlier this week that some of the profits would go to two appointed charities as well as a trust for Jackson's children.
While acknowledging that the difficulties had taken some of the gloss off the event, fans gathering outside the stadium were excited to be able to pay homage to their idol.
"He was the best there is," said Kerry Hall-Smith, from Cardiff, who had a special T-shirt printed for the event.
"He's one of the legends, he's like Elvis. They are the people you remember forever." (Reuters)
