Nirvana survivors to back Paul McCartney during 12-12-12 benefit

The surviving members of Nirvana haven't played together since frontman Kurt Cobain's suicide nearly 20 years ago, but they'll be on stage to back ex-Beatle Paul McCartney during tonight's 12-12-12 benefit concert in New York City for Hurricane Sandy victims.

Various outlets in the U.K. are reporting that Nirvana bassist Krist Novoselic, drummer Dave Grohl and touring guitarist Pat Smear have been working on a song in secret with McCartney, 70, and will perform it live for the first time tonight.

According the The Sun, McCartney said he called Grohl and suggested they "just make something up," and Grohl asked to bring along "some mates" to jam.

Those "mates" turned out to be Novoselic and Smear.

"I didn't really know who they were," McCartney said. "They are saying how good it is to be back together. I said 'Whoa? You guys haven't played together for all that time?' And somebody whispered to me, 'That's Nirvana. You're Kurt.' I couldn't believe it."

Don't expect McCartney to belt out any Nirvana songs, however. According to reports, that's not in the plans.

Among the others on the bill for tonight's 12-12-12 show at Madison Square garden are The Rolling Stones, Bruce Springsteen, Kanye West, Billy Joel and Eric Clapton.

Organizers claim that 2 billion people worldwide will have the ability to watch the concert, which starts at 7:30 p.m. ET tonight (12/12).

The the show will air on 34 U.S. networks, and TV feeds will be made available to other networks in North and South America, as well as Asia, Europe, Africa and Australia. The show will also be simulcast for free in select theaters, and streaming online via various outlets.

For more information about where the show can be viewed and how to donate to support storm victims, visit the event's official website.