Christina Aguilera, Cee Lo Green and Motown veteran Smokey Robinson are set to perform at a tribute concert in honour of Michael Jackson.
More acts will be added to the bill nearer the time, organisers of the Michael Forever concert said.
Jackson's brothers have protested to the timing of the event which coincides with the trial of the Dr Conrad Murray, charged over the singer's death.
The gig takes place at Cardiff's Millennium Stadium on 8 October.
While the concert has raised the doubts of Randy and Jermaine Jackson, it has the full support of the star's mother and other siblings.
British acts Leona Lewis, Craig David and JLS have also been lined up to perform at the gig.
Several of Jackson's brothers will also perform, along with 3T, which consists of Tito Jackson's three sons.
Rock band Alien Ant Farm, who had a hit with a cover version of Jackson's Smooth Criminal, will also appear at the concert.
"We're delighted that such exciting and globally recognised acts have joined the line-up to pay tribute to a music legend," said Chris Hunt, president of concert promoter Global Live Events.
The concert will raise awareness and funds for Aids Project Los Angeles and two other charities, which have yet to be announced.
Jackson died in June 2009 at the age of 50 while rehearsing for his This Is It tour.
A Jackson tribute concert, expected to take place in Vienna in September 2009, was cancelled after organisers failed to attract major names to perform at the event.