Earth, Wind & Fire happens to be in the area and offered to play on the popular music festival's largest stage on Friday night.
Festival spokesman Louis Edwards says the "Queen of Soul" told organizers on Thursday that she wouldn't be able to perform. Edwards said she apologized to fans but wouldn't give a reason why.
But Earth, Wind & Fire were already scheduled to play Saturday in Biloxi, Miss., about 65 miles away. They played Jazz Fest last year to rave reviews.
Pearl Jam is scheduled to headline Saturday, and the setwill be broadcast live online to Louisiana National Guard soldiers serving in Iraq.