Paul McCartney did his best Kurt Cobain impersonation on Wednesday night, joining Nirvana's Dave Grohl and Krist Novoselic for a spirited performance at the 12-12-12 concert. The special development closed the show, which benefits victims of Hurricane Sandy.
McCartney first took the stage to perform "Helter Skelter." He was later joined by Diana Krall, with whom he performed "My Valentine." But eventually, it was time: Grohl, Novoselic and Pat Smear took the stage. The men did a new song, "Cut Me Some Slack," which they said was never before performed for an audience. The performance didn't happen until 1:00 a.m., surprising given Madison Square Garden's notoriously strict curfews. It was a boisterous show, with McCartney looking pretty much amazing for his 70 years.
After the new song, called "Cut Me Some Slack," McCartney went back to his own band.
Rumors that Sir Paul was joining the group for Wednesday's event sparked a Twitter frenzy. A spokesman for Grohl told the Guardian that the Beatle had joined Novoselic and the Foo Fighter's frontman in the studio.
McCartney, however, didn't really seem to know what he had gotten himself into. "I didn't really know who they were," he 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.'"
Certain headlines and media reports that McCartney was "reuniting" or "joining" Nirvana seem a bit bloated -- all indications point to the collaboration centering on 12-12-12 and a potential song.
Nirvana frontman Kurt Cobain committed suicide on April 5, 1994. His body was discovered three days after, next to a suicide note. The grunge band continues to be a fan favorite, and Cobain remains a cult hero.
The concert, which took place at New York's Madison Square Garden, was live streamed on a variety of outlets. Organizers hoped the show would reach a potential audience of 2 billion.

US-MUSIC-CONCERT FOR SANDY RELIEF
Paul McCartney performs on stage during the finale of '12-12-12 ~ The Concert For Sandy Relief' December 12, 2012 at Madison Square Garden in New York. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Roger Daltrey of The Who performs at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Roger Daltrey of The Who performs at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Roger Daltrey of The Who performs at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Roger Daltrey of The Who performs at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Roger Daltrey of The Who performs at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Roger Daltrey of The Who performs at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Roger Daltrey (L) and Pete Townshend of The Who perform at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
US-MUSIC-CONCERT FOR SANDY RELIEF
Roger Daltrey (L) and Pete Townshend (R) of The Who perform during '12-12-12 The Concert For Sandy Relief' December 12, 2012 at Madison Square Garden in New York. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Roger Daltrey of The Who performs at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
US-MUSIC-CONCERT FOR SANDY RELIEF
Roger Daltrey (L) and Pete Townshend (R) of The Who perform during '12-12-12 The Concert For Sandy Relief' December 12, 2012 at Madison Square Garden in New York. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)
US-MUSIC-CONCERT FOR SANDY RELIEF
Roger Daltrey (L) and Pete Townshend (R) of The Who perform during '12-12-12 The Concert For Sandy Relief' December 12, 2012 at Madison Square Garden in New York. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)
US-MUSIC-CONCERT FOR SANDY RELIEF
Scenes of relief operations amid Hurricane Sandy are projected as The Who perform during '12-12-12 The Concert For Sandy Relief' December 12, 2012 at Madison Square Garden in New York. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)
US-MUSIC-CONCERT FOR SANDY RELIEF
The Who perform during '12-12-12 The Concert For Sandy Relief' December 12, 2012 at Madison Square Garden in New York. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)
US-MUSIC-CONCERT FOR SANDY RELIEF
A video of New Jersey Governor Chris Christie (R) speaking to a victim of Hurricane Sandy is projected as The Who perform during '12-12-12 The Concert For Sandy Relief' December 12, 2012 at Madison Square Garden in New York. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)
US-MUSIC-CONCERT FOR SANDY RELIEF
Roger Daltrey (L) and Pete Townshend (R) of The Who perform during '12-12-12 The Concert For Sandy Relief' December 12, 2012 at Madison Square Garden in New York. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)
US-MUSIC-CONCERT FOR SANDY RELIEF
The Who perform during '12-12-12 The Concert For Sandy Relief' December 12, 2012 at Madison Square Garden in New York. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)
US-MUSIC-CONCERT FOR SANDY RELIEF
A video of US President Barack Obama speaking to victims of Hurricane Sandy is projected as The Who perform during '12-12-12 The Concert For Sandy Relief' December 12, 2012 at Madison Square Garden in New York. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Musicians Bruce Springsteen (L) and Jon Bon Jovi perform at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Jon Bon Jovi performs at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Richie Sambora and Jon Bon Jovi perform at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Richie Sambora and Jon Bon Jovi perform at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Musician Jon Bon Jovi performs at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Musicians Bruce Springsteen, Jon Bon Jovi and Max Weinberg perform at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Musician Jon Bon Jovie at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Musicians Bruce Springsteen, Jon Bon Jovi and Max Weinberg perform at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Musicians Bruce Springsteen, Jon Bon Jovi and Max Weinberg perform at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Musician Jon Bon Jovi performs at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Musician Jon Bon Jovi performs at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Musician Jon Bon Jovi performs at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Musicians Jon Bon Jovi (L) and Bruce Springsteen perform at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
US-MUSIC-CONCERT FOR SANDY RELIEF
Jon Bon Jovi (R) performs during '12-12-12 ~ The Concert For Sandy Relief' December 12, 2012 at Madison Square Garden in New York. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)
US-MUSIC-CONCERT FOR SANDY RELIEF
Jon Bon Jovi performs during '12-12-12 The Concert For Sandy Relief' December 12, 2012 at Madison Square Garden in New York. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)
US-MUSIC-CONCERT FOR SANDY RELIEF
Jon Bon Jovi performs during '12-12-12 ~ The Concert For Sandy Relief' December 12, 2012 at Madison Square Garden in New York. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Musician Jon Bon Jovi performs at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
US-MUSIC-CONCERT FOR SANDY RELIEF
Jon Bon Jovi (L) and Bruce Springsteen (R) perform during '12-12-12 ~ The Concert For Sandy Relief' December 12, 2012 at Madison Square Garden in New York. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)
US-MUSIC-CONCERT FOR SANDY RELIEF
Jon Bon Jovi performs during '12-12-12 ~ The Concert For Sandy Relief' December 12, 2012 at Madison Square Garden in New York. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)
US-MUSIC-CONCERT FOR SANDY RELIEF
Jon Bon Jovi performs during '12-12-12 ~ The Concert For Sandy Relief' December 12, 2012 at Madison Square Garden in New York. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)
US-MUSIC-CONCERT FOR SANDY RELIEF
Jon Bon Jovi (L) and Bruce Springsteen (R) perform during '12-12-12 ~ The Concert For Sandy Relief' December 12, 2012 at Madison Square Garden in New York. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)
US-MUSIC-CONCERT FOR SANDY RELIEF
Jon Bon Jovi performs during '12-12-12 ~ The Concert For Sandy Relief' December 12, 2012 at Madison Square Garden in New York. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Bruce Springsteen performs at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Musicians Bruce Springsteen (L) and Jon Bon Jovi and Max Weinberg perform at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
US-MUSIC-CONCERT FOR SANDY RELIEF
Bruce Springsteen performs during '12-12-12 ~ The Concert For Sandy Relief' on December 12, 2012 at Madison Square Garden in New York. AFP PHOTO / DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Bruce Springsteen performs at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Nils Lofgren,and Bruce Springsteen perform at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Musicians Bruce Springsteen (L) and Jon Bon Jovi perform at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
US-MUSIC-CONCERT FOR SANDY RELIEF
Jon Bon Jovi (L) and Bruce Springsteen (R) perform during '12-12-12 ~ The Concert For Sandy Relief' December 12, 2012 at Madison Square Garden in New York. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Bruce Springsteen performs at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Bruce Springsteen performs at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)
US-MUSIC-CONCERT FOR SANDY RELIEF
Bruce Springsteen (L) and Steven Van Zandt (R) perform during '12-12-12 ~ The Concert For Sandy Relief' December 12, 2012 at Madison Square Garden in New York. AFP PHOTO/DON EMMERT (Photo credit should read DON EMMERT/AFP/Getty Images)
12-12-12 Concert Benefiting The Robin Hood Relief Fund To Aid The Victims Of Hurricane Sandy - Show
NEW YORK, NY - DECEMBER 12: Nils Lofgren, Bruce Springsteen, and Steven Van Zandt perform at '12-12-12' a concert benefiting The Robin Hood Relief Fund to aid the victims of Hurricane Sandy presented by Clear Channel Media & Entertainment, The Madison Square Garden Company and The Weinstein Company at Madison Square Garden on December 12, 2012 in New York City. (Photo by Larry Busacca/Getty Images for Clear Channel)



The Huffington Post | By Kia Makarechi Posted: 12/13/2012 1:09 am EST | Updated: 12/17/2012 12:22 pm EST