Singer Stevie Wonder was due to perform at a New Orleans concert to mark one year since Hurricane Katrina devastated the Gulf coast of the US.
Wonder will close the concert with a 30-minute set
The Motown star and local musicians, including jazz trumpeter Winton Marsalis, were lined up to perform at the Rebuilding the Soul of America gig.
The show was set to benefit a trust set up by Marsalis to rebuild the cultural infrastructure of the Louisiana city.
A film about the hurricane, narrated by Meryl Streep, also opened.
Hurricane on the Bayou was made as the weather system devastated New Orleans, and is set to open around the world in December.
Other artists due to perform at the concert on Tuesday included New Orleans-born blues singer Dr John, Grammy award-winning gospel performer Yolanda Adams and keyboardist Ivan Neville, son of Aaron Neville and also a New Orleans native.
Promoters for the event admitted that sales for the concert, which was announced earlier this month, were slower than expected.
Bill McFarlin, one of the organisers, says "information overload" about the wealth of events taking place to mark the first anniversary has contributed to disappointing sales.
Meryl Streep's narration will touch upon Louisiana culture
The original plan to have 10,000 seats was reduced to 6,000.
Mr McFarlin said that 3,500 seats had been reserved by Monday morning.
Musician Ivan Neville, whose family was displaced by Katrina, has called the concert "one small step" towards helping people recover from the devastation of the hurricane.
He added that the city's musical tradition was being held up as New Orleans is gradually rebuilt.
"We're losing a generation of musicians. We've got to pass it along like it was passed to us."
Earth, Wind and Fire were originally on the line-up, but had to pull out due to a scheduling clash.