Only at a Rolling Stones concert could appearances by Bruce Springsteen and Lady Gaga seem almost like afterthoughts.
Those superstars and other top acts including the Black Keys and John Mayer jammed with the Stones on Saturday night, winding down a series of concerts celebrating the 50th year of rock's most enduring band.
The Boss rocked out with the band on out Tumbling Dice; Gaga matched Mick Jagger shimmy-for-shimmy on Gimme Shelter; the Black Keys joined on Who Do You Love, and John Mayer and Gary Clark Jr showed their considerable guitar chops alongside Keith Richards and Ronnie Wood on Goin' Down.
But the Stones would not be upstaged.
While the sold-out crowd roared with each special guest, it was the aging but dynamic foursome that generated the most excitement of the night, as they put new energy into their decades-old catalogue of hits, including It's Only Rock 'N Roll (But I Like It), Start Me Up, Brown Sugar, Sympathy for the Devil and more.
The band took a moment to acknowledge the shooting deaths of 20 children and six adults at a school Friday in Newtown, Connecticut.
"We just wanted to send our love and condolences to all the people who lost loved ones in the tragedy in Connecticut," Jagger early on in the concert as the audience applauded.
Jagger noted the entire world was feeling the pain of the stunned nation.
But it was the only sombre moment in an a frenetic show that showed why the Stones are considered by many to be the greatest rock band, and belied the much-discussed advanced age of the group's line-up (their ages range between 65 and 71).
Jagger himself poked fun at the senior citizen status of the band and their fans; speaking of the pay-per-view crowd at home, he joked: "Some of you have got your grandchildren watching you."
But few acts in their so-called prime would have been able to match the energy the Stones radiated onstage. The group had the crowd on its feet for the entire show as Jagger gyrated across the stage, his voice in top form. Both Wood and Richards dazzled on guitar (Richards got a raucous, sustained ovation as he took over vocals on two songs). And Charlie Watts kept the beat strong on the drums.
Before performing in London together late last month for the first of the concerts, the Stones hadn't performed in concert together since 2007.
Going into these shows, there was some speculation that Saturday's concert, held at the Prudential Center, might be their last.
Earlier in the evening, Jagger teased that the concert might signal the end: "This could be the last time; I don't know," he said. But by the end of the evening, it seemed clear that the question was not when the Stones would return, but when.
"This is the last show of our anniversary tour, and we hope to see you all again soon," Jagger said.
Perhaps the night's most special guest was Mick Taylor, the former Stones guitarist who was part of some of their biggest moments from 1969 to 1975, when he left the group. He rejoined his band mates (and the man who replaced him, Wood) onstage for a powerful performance of Midnight Rambler.
At the concert's end, while other special guests gave their final bows and left the stage, Jagger motioned for Taylor to stay, and the five took their final bow together.