Paul McCartney fronts Nirvana reunion

Ex-Beatle Paul McCartney teamed up with remaining members of Nirvana, at a charity gig for Hurricane Sandy in New York (December 12).
Foo Fighters' frontman Dave Grohl was present along with Krist Novoselic, whilst McCartney replaced Kurt Cobain on vocals. McCartney has said "So recently, some guys asked me to go and jam with them. I finally understood that I was in the middle of a Nirvana reunion."
It has been reported that McCartney rang Grohl and asked him to jam. McCartney, unaware of what he was getting himself into to, turned up to the session with Grohl on drums, Novoselic on bass, Pat Smear on guitar and Sir Macca himself fronting the group.
 He spoke out saying "I didn't really know who they were. 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."
Other artists who played the gig included: The Rolling Stones, Bruce Springsteen, Bon Jovi, Green Day, Kanye West and The Who. Roger Waters also played and was joined in his set by Pearl Jam's Eddie Vedder.

What do you think of Paul McCartney fronting Nirvana? Do you think anyone can replace Kurt? Have you seen footage of this gig? Comment below.