John Lennon's son Sean hit the streets of New York with fellow musician Rufus Wainwright on Sunday to serenade the Occupy Wall Street protesters with an acoustic version of Madonna's Material Girl.
The singers became the latest stars to lend their support to the demonstrators campaigning against social inequality and corporate greed, and they put on an impromptu performance in Manhattan's Zuccotti Park, which has become a makeshift base for protesters.
Lennon and Wainwright were accompanied by a number of guitarists and an accordion player as they belted out the odd song choice.
They weren't the only celebrities to join the activists this weekend - veteran folk star Pete Seeger entertained campaigners in the early hours of Saturday by performing protest song "We Shall Overcome," while rap mogul Russell Simmons, comedian Russell Brand and his pop star wife Katy Perry were also among those spotted at Zuccotti Park.
The growing list of celebrity supporters has included Susan Sarandon, rocker Tom Morello, Kanye West, Alec Baldwin and Tim Robbins.