There are rumors that the greatest thing ever may happen tonight at the 12-12-12 Hurricane Sandy benefit concert tonight at New York City's Madison Square Garden. Nirvana musicians Dave Grohl, Krist Novoselic and Pat Smear will reportedly take the stage tonight with Beatles legend Paul McCartney for a once-in-a-lifetime performance.

According to British tabloid The Sun, McCartney will front a Nirvana reunion of sorts tonight, filling in for the late Kurt Cobain, who died in 1994. However, the musical collective will not be performing a Nirvana song, but a new original tune instead.

McCartney reportedly called Dave Grohl for a chat, which led to the Nirvana drummer and Foo Fighters frontman inviting McCartney for an impromptu jam session with Novoselic and Smear. "I didn't really know who they were," begins McCartney. "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."

The story may seem bizarre, but it has generated worldwide buzz for what could be one of the great performances of our time. NME magazine even asked fans on Twitter to come up with their own Nirvana/Beatles song titles, with hilarious mashups such as 'Sgt. Peppers Lonely Heart-Shaped Box,' Penny Lane Royal Tea' and 'You've Got to Hide Your Courtney Love Away' having already been conceived.

In other 12-12-12 news, Pink Floyd legend Roger Waters confirmed on 'Jimmy Fallon' last night that he would be performing with Pearl Jam's Eddie Vedder at the charitable event.

The 12-12-12 concert can be seen on a number of television channels tonight at 7:30PM ET. It will also be streaming on several websites. Click here for more info.