This just in from the Hollywood Bowl PR:
Youssou N’Dour, who was scheduled to appear on the KCRW World Festival series at the Hollywood Bowl on July 27, 2008, has been forced to cancel his upcoming U.S. tour due to unanticipated schedule conflicts. N’Dour is replaced by Senegalese singer Fallou Dieng. Deerhoof opens the show and Gnarls Barkley headlines.
Here's something from Dieng: