The pair took to the stage at the Hyatt Regency for the A Night to Make It Right charity gala, which featured show-stopping performances from singers Rihanna, Sheryl Crow and Seal.
Famous faces including actors Sean Penn and Kevin Spacey and filmmaker Spike Lee also turned up to lend their support, paying upwards of $1,000 (£625) a seat.
Later on guests headed to a fundraising after-party for more music by Kanye West and Snoop Dogg, and Pitt admits he was overwhelmed by the outpouring of generosity.
He tells Reuters, "Even though these people don't like me that much, it really was simple. They carved this time out of their schedule strictly for this event, and came on their own dime."
The actor estimates that both events raised $4 million (£2.5 million) for his Make It Right organisation, which was launched in 2005 in an effort to rebuild the area in the wake of Hurricane Katrina.