More celebs join the amazing event!

FOX announced more of their all-star lineup for the special "Idol Gives Back" charity show, airing Wednesday, April 9, which will include ROBIN WILLIAMS in one of his first appearances since news of his divorce broke Wednesday. Also joining the feel-good event ...

CELINE DION, FOREST WHITAKER, BILLY CRYSTAL, KIEFER SUTHERLAND, DANE COOK, VANESSA HUDGENS, ASHLEY TISDALE and former "Idols" ELLIOTT YAMIN and FANTASIA.

The show, being co-hosted by ELLEN DEGENERES and RYAN SEACREST, tapes Sunday, April 6 at Hollywood's Kodak Theatre. Last season, Idol raised over $76 million and received a special Governor's Award Emmy. All proceeds go to various U.S. and international charities, including the Children's Defense Fund, The Global Fund to Fight AIDS, Tuberculosis and Malaria, Make It Right,  Malaria No More, Save The Children, and the Children's Health Fund.