Nirvana reunification for Wednesday night's special Hurricane Sandy relief concert at Madison Square Garden will see Paul McCartney fill the boots of the late Kurt Cobain. 

Nirvana's Dave Grohl asked McCartney to join him and Krist Novoselic on stage for the special 12-12-12 event. The Rolling Stones, The Who, Alicia Keys, Eric Clapton, Kanye West, Roger Waters, Jon Bon Jovi and Billy Joel are also expected to perform during the star-studded event. And producers believe viewing figures for the program could reach 2 billion. "I didn't really know who they were," the 70-year-old Beatles legend told The Sun. "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." Cobain remains on of music's most talked about and glorified artists after Nirvana pioneered grunge in the early 90's before his suicide in 1994.

The four year period between 1990-94, bookended by Dave Grohl joining the band and Cobain's untimely death saw the Seattle band's most fruitful period, as they produced the evergreen hit Smells Like Teen Spirit. Since then Grohl started The Foo Fighters, and has enjoyed tremendous success, but playing the hits at tonight's Sandy benefit will surely provide a hit of nostalgia and a tinge of sadness to go with it.