Tom Waits, Dave Matthews, Trey Anastasio, John Mayer Trio, Joss Stone and the Meters have signed on for a Sept. 20 benefit concert for Hurricane Katrina victims at New York's Radio City Music Hall. The event will be held simultaneously with a previously announced benefit at the city's Madison Square Garden.

Also on the bill for the Radio City show are Galactic with the Mardi Gras Indians and Ray Lamontagne. Tickets go on sale Thursday (Sept. 15) via Ticketmaster.

Meanwhile, a host of top acts have joined the bill for the Madison Square Garden event, including Simon & Garfunkel, who will be making their first live appearance since the July 2004 conclusion of their Old Friends reunion tour.

They will be flanked by new additions Elvis Costello, Diana Krall, Kermit Ruffins, Irma Thomas, Clarence "Frogman" Henry, Dave Bartholomew and Troy "Tromboneshorty" Andrews. Among the previously announced acts are Elton John, Jimmy Buffett, John Fogerty, Lenny Kravitz, Ry Cooder, Stevie Nicks, Fats Domino and Bette Midler.

Although organizers say Rod Stewart has dropped off the bill "due to injury," a spokesperson for the artist says he will be recovering from shoulder surgery and has been advised by doctors not to return to the stage just yet.

Proceeds will be donated to such organizations as the Bush Clinton Katrina Fund, Habitat for Humanity, the MusiCares Hurricane Relief Fund and the Children's Health Fund.