12.12.12 Sandy Benefit Concert: Photos of Bruce Springsteen, Paul McCartney And More [SLIDESHOW AND VIDEOS]

The "12.12.12 Concert," which was billed as the "biggest music event ever," was seen on Wednesday night by an estimated two billion people worldwide via broadcasts and online live streams. On hand at Madison Square Garden in Manhattan were some of the biggest names in movies, television, music and sports.

The Hurricane Sandy benefit concert featured several entertainers including Paul McCartney, Bruce Springsteen, Kanye West, Billy Joel, the Who, the Rolling Stones, Bon Jovi, Alicia Keys, Dave Grohl, Eric Clapton and Roger Waters. The "12.12.12 Hurricane Sandy Benefit Concert" raised money for the Robin Hood Foundation, which is helping other tri-state charities, and organizing Hurricane Sandy Relief efforts.

The "12.12.12" concert lived up to early expectations. There were plenty of surprise collaborations, such as Eddie Vedder, from Pearl Jam, working with Roger Waters, from Pink Floyd, to the highly anticipated Nirvana reunion with Dave Grohl, Kirt Novoselic and Pat Smear joining Paul McCartney. While it was not originally announced, two Jersey boys did collaborate on stage as well -- Bruce Springsteen and Bon Jovi.

While many fans were waiting to hear a few Nirvana tunes, with McCartney on vocals, it was not meant to be. Instead, the Nirvana reunion lasted for just one song. While that song, "Cut Me Some Slack," did sound a little like Nirvana, it did not live up to the wild speculation of McCartney singing some of Nirvana's favorite hits, such as "Smells Like Teen Spirit" or "Heart Shaped Box." Nirvana was not the only guest to share the stage with McCartney. McCartney invited Hurricane Sandy first responders up on stage as well to share the moment.

While the focus of "12.12.12" was on the music and Hurricane Sandy, there were plenty of stars from across film, television and sports that made an appearance and spoke about Hurricane Sandy and the relief efforts. Celebrities making appearances included Billy Crystal, Adam Sandler, Stephen Colbert, Kristen Stewart, Blake Lively, Jon Stewart, Katie Holmes, Andy Sudekis, Chris Rock, P. Diddy and Jimmy Fallon.

The benefit concert, which ran more than six hours, had been considered an epic spectacle for a worthy cause. The sheer amount of effort needed to organize and hold the event, the wide range of talent involved, both on stage and behind the scenes to produce the show, aimed to inspire a region devastated in October by Hurricane Sandy. The storm slammed New York, New Jersey and Connecticut. and recovery efforts are continuing. The "12.12.12" benefit helped raise awareness and money for the Robin Hood Relief Foundation, and it gave hope that people will be united in the ongoing recovery efforts following Hurricane Sandy.

Check out some of the videos below of several performers from last night's benefit concert, including Paul McCartney and Nirvana playing "Cut Me Some Slack."