One moment Ronnie Wood was on stage playing guitar with a host of his old music mates he's known since his days with the Faces.
The next minute old Jumping Jack Flash himself, Mick Jagger, leaped up onto the stage to join his fellow Rolling Stone for an encore.
With Stones concerts now restricted to super-sized stadiums, this was like the old days: Mick, Ronnie and friends jamming in the intimate setting of a London theatre.
Wood, clad in tight denim and cut-off white T-shirt, and Jagger, in open-necked shirt and black trousers, brought back memories of the Stones at their height.
After quitting the Faces in 1975, Wood teamed up with the Stones to record albums including Black And Blue, Some Girls, Tattoo You and Voodoo Lounge.
For some people in the audience last night that was ancient rock and roll history but that didn't stop them having a good time.
Guests included actress Davinia Murphy, ubiquitous party girl Meg Mathews, singer Andrea Corr and Elton John percussionist Ray Cooper.
Jagger's girlfriend L'Wren Scott and various members of the Wood clan were also there and went on to party at the Aura club afterwards.
It may have only been rock'n'roll, but they loved it.