Massive Attack and Thom Yorke back Occupy London protest
Occupy London protesters camped outside St Paul's have been backed by Massive Attack and Radiohead's Thom Yorke at a "secret" gig.
The artists wanted to "thank" activists protesting against corporate greed.
A small audience of about 100 people saw the performance at an undisclosed location in London.
Protesters moved into St Paul's Churchyard on 15 October, Finsbury Square on 22 October and an empty bank building in Hackney on 18 November.
Tim Goldsworthy, of the collective Unkle, also performed at the gig for a downloadable album.
The activists said the set would be available online from Wednesday.
Their demonstration is part of a worldwide movement, which began on New York's Wall Street.
Last month, the City of London Corporation resumed legal action against the camp, after talks failed in attempts to remove them.
The corporation said it had received complaints about "late-night drinking and other worrying trends, so it's time to act".
"Lawful protesters who stand or walk are a regular part of London," said Stuart Fraser, policy chairman of the corporation.
"But tents, equipment and now, increasingly, quite a lot of mess, is not what a highway is for and others are losing out."
Other celebrities who have backed the protesters' campaign include fashion designer Vivienne Westwood.