Those superstars and other top acts including the Black Keys and John Mayer jammed with the Stones at the weekend, winding down a series of concerts celebrating the 50th year of rock's most enduring band (the occasion was also marked by a pay-per-view special).
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 ageing 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 an elementary school in Newtown, Conn. "We just wanted to send our love and condolences to all the people who lost loved ones in the tragedy in Connecticut," said Jagger.
But it was the only sombre moment in a frenetic show that 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."
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.