More than any rapper and more than most pop stars, Jay-Z knows the significance of a moment.

The Brooklyn MC’s career is practically defined by them. There’s his Summer Jam obliteration of Mobb Deep’s Prodigy back in 2001, the same year he brought out Michael Jackson for Hot 97’s annual concert. There was his retirement show at Madison Square Garden captured in the documentary Fade to Black. And then there was his Radio City Music Hall show to celebrate the 10-year anniversary of Reasonable Doubt. And who could forget the Best of Both Worlds fiasco with R. Kelly that turned into the celebrated Jay-Z and Friends jaunt. He’s even transformed festivals into his personal showcases, with his appearance at Glastonbury last year and All Points West this year.

But when Hov announced he’d be headlining a September 11th benefit show, to not only coincide with the anniversary of his classic album The Blueprint but also to mark the release of his latest effort, The Blueprint 3, one had to wonder if this ambitious slate reeked of opportunism.

It did not.

Last night at the Garden, Jay-Z delivered a carefully orchestrated and riveting show striking the the impossibly difficult balance of serving the cause and seizing another night that will stand out in his long list of historic performances.

“We celebrating life tonight, we having a good time,” Jay-Z told the sold-out audience, which included Diddy, Justin Timberlake, Katy Perry and Chris Rock, among other celebrities. “But let’s not forget in 2001 when the first Blueprint came out terrorist attacked New York. They thought they would weaken us. They were sadly mistaken. We stand here even stronger. This is our town. We run New York City. We run this town.”

And with that, the blaring Rihanna’s wailing voice boomed over the sound system. The “Umbrella” star then appeared under the spotlight decked out in a dominatrix-like black outfit. “We are, yeah I said it, We are, This is Roc Nation, pledge your allegiance,” Jay-Z rapped.

Kanye West joined the pair toward the end of the song, completing the triumvirate as he jumped from the stairs on the middle of the stage. ‘Ye stuck around for a few more songs, diving into “Can’t Tell Me Nothing” before asking Big Brother if he can keep going.

“Let’s do it,” Jay replied.

“Good Life” then came on, sans T-Pain, and an animated West — complete with a new ‘do, with zig-zag lines cut into his hair — fumbled a few of his lines but saved himself with an impromptu freestyle. “I fucked up the flow, but everybody know, I gotta give a shout out to my big bro,” he spit, drawing a smile from Jay.

The parade of guest appearances continued with Pharell Williams, Swizz Beatz and Mary J. Blige joining Jay-Z. John Mayer also popped up to play guitar for Jay-Z on “D.O.A. (Death of Auto-Tune).”

Throughout the set, Jay-Z dipped into catalog but also performed new songs from his recently released BP3. Upstart Kid Cudi arrived onstage to assist Hov on “Already Home,” where the legendary rapper eviscerates mouthy MCs who say Jay-Z’s tenure on top is in the way of their rise to fame.

“These niggas want me to go, don’t they know that I’m gone/ They know that I’m space shuttle level, they need oxyggggon/Don’t they know that I yawn/ Only time they exciting is when they mentioning Shawn,” he rapped.

The Timbaland-produced “Venus vs. Mars” was another new tracked Jay-Z performed. He closed the song out with a new freestyled verse at the end where he name-checked Kanye’s lady friend Amber Rose and financial villain Bernie Madoff. Seconds after he finished, Beyoncé, featured on the song’s chorus, emerged from the bowels of the Garden rising up through a trap door to perform “Diva.”

The star wattage was bright but the greatest applause of the night came in honor of the service men and women who protect our country on this tragic date eight years ago.

As “Young Forever” spilled out over the arena speakers, a beautiful montage of firefighters and police officers who lost their lives on 9/11 eight years ago appeared behind Jay-Z on a huge screen. “Make some noise for those that lost their lives so we could live ours,” Jay-Z said.