Image Credit: Kevin Mazur/WireImage.comThe cake had been served, the candles had been blown out, and Ringo Starr had all but told the sold-out crowd at NYC’s Radio City Music Hall to go home, but the most exciting part of his 70th birthday show last night was still to come. That was the exact moment, right around 10 p.m., that none other than Paul McCartney bounded on stage in his skinny tie and fitted suit. The art-deco hall filled with 1964-style squeals as Sir Paul tore through the Beatles’ “Birthday” with the wild-eyed drive of someone decades younger.

McCartney’s unannounced appearance was the perfect end to an evening of festive collaboration. Ringo calls his touring act the All-Starr Band for a reason: They’re all handpicked veterans of bands from the ’60s, ’70s, and ’80s. In between his solo hits (“Photograph,” “It Don’t Come Easy”) and Beatles classics (“Yellow Submarine,” “Act Naturally,” “Boys”), he gave each of his bandmates ample time to demonstrate their own claims to fame. Keyboardist/saxophonist Edgar Winter led electrifying renditions of “Frankenstein” and “Free Ride.” Guitarist Rick Derringer of the McCoys rocked “Hang On Sloopy.” The Romantics’ Wally Palmar told us “What I Like About You.” Mr. Mister’s Richard Page spread his “Broken Wings.” Gary Wright crooned “Dreamweaver,” which he said was inspired by a book on Eastern philosophy that George Harrison once gave him. (“George Harrison never gave me no damn book,” cracked Ringo.) I’m not sure I’d sit through an entire concert by any of those guys’ original groups, but seeing them run through their hits with Ringo was fun — a classic-rock radio revue with one of history’s greatest beat-keepers behind the kit. Starr himself was as energetic as any 70-year-old I’ve ever encountered, grooving gamely at front stage or drumming with that familiar head-bobbing enthusiasm.

Halfway through a Mr. Mister song, my mother and I noticed the E Street Band’s Stevie Van Zandt and Nils Lofgren and ELO’s Jeff Lynne simultaneously leaving their seats a few rows ahead of us. For a moment I thought they must not be big “Broken Wings” fans, but of course they were only heading backstage. A few numbers later, Starr said he wanted to play a tune that he was considering cutting from his set list due to lukewarm crowd reactions. The song was “With A Little Help from My Friends.” Oh, Ringo, you joker! This was the cue for a cavalcade of celebs to join him. Seeing Starr giddily jam with Van Zandt, Lofgren, Lynne, Yoko Ono, Joe Walsh, and quite a few others is not a sight I’ll soon forget.

My mother and I had been hoping all along that McCartney might pop up. He was conveniently in between tour dates in London and San Francisco this week, and 70 is a big birthday. But “With A Little Help” transitioned into a sweet singalong of John Lennon’s “Give Peace a Chance,” followed by a spontaneous crowd rendition of “Happy Birthday” and the aforementioned cake and candles, and Macca was nowhere to be seen. Oh well. Who could complain after all those other guests? And then he turned up after all. His “Birthday,” with Walsh on wicked lead guitar, was the best possible way to end that show. Afterward, teary hugs were exchanged between McCartney, Starr, and Ono. McCartney softly repeated the words “Happy birthday to you” into the microphone. The appreciative surprise on his old friend’s face looked altogether genuine.

And so, for the second time in as many years, the two surviving Beatles shared a concert stage. (The same stage, as it happens.) My mom, who never got to see them when she was a teenaged fan in the ’60s, was pretty psyched to be there. So was I. On our way out from the venue, someone was raving about “history in the making.” Were any of you lucky enough to see last night’s show? If not, console yourself with the extremely shaky fan video of “Birthday” below. UPDATE: Replaced with a much clearer fan video.

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