The lineup of the star-studded 12-12-12 Hurricane Sandy relief concert set to take place in New York City later this month keeps getting more studded with stars. Last week Foo Fighters frontman Dave Grohl and Pearl Jam singer Eddie Vedder signed on for 12-12-12, and now Coldplay's Chris Martin and classic rocker Eric Clapton are the latest rockers to join the bill.

The 12-12-12 concert is scheduled to take place Dec. 12 at Madison Square Garden, with all proceeds benefiting the Robin Hood Relief Fund in aid of victims of Sandy, which devastated the New York and New Jersey coast in late October. Tickets for the gig, which also will feature performances from  Bruce SpringsteenPaul McCartney, the Who and many other artists, went on sale to the general public today noon.

"We are grateful to each and every artist that has agreed to be part of this historic night -- the response has been astounding," event producers James Dolan, John Sykes and Harvey Weinstein said in a joint statement. "We are just now starting to understand the true scope and devastating impact that Hurricane Sandy brought to the tri-state area and we hope, through this tremendous and unprecedented concert event, to provide the most assistance possible."