She's planning special guests, an entire brass horn section to back her up, and a soulful set list for Friday night's show, including "Lady Marmalade," the LaBelle song she helped remake into a hit years ago.
"It will be exciting to perform 'Lady Marmalade' here, as this is where the writers of the song were inspired," she said in an email statement about her performance.
Festival producer Quint Davis said he hand-picks artists for the festival who he thinks will suit the experience. He called Aguilera "one of the great vocalists of our era."
"That's what I look for, greatness," he added.
Other performers scheduled for Friday include soul great Chaka Khan, the rock group the Alabama Shakes and Louisiana-based acts including the Charmaine Neville Band, Amanda Shaw and the Hot 8 Brass Band.
One of Aguilera's "guests" will be her unborn daughter; she's several months pregnant with her second child, whom she already calls a "roadie."
"This baby girl has already hit the stage in Malaysia," she said in the email. "It's mama's job. We roll with it. She'll be listening to the concert from inside me. ... that's pretty special."
The festival ends on Sunday.
Associated Press writer Stacey Plaisance contributed to this report.