A secret film shoot with Leonard Cohen in New York.

They hardly ever get a day off but yesterday, in between a clutch of shows in the New York area, U2 got together to do some recording with legendary singer-songwriter Leonard Cohen.

Filming for an upcoming documentary on Cohen, directed by Lian Lunson, the band turned up in a burlesque lower east side venue known as 'The Slipperoom Club.'

Passers by could barely believe it as the cars arrived in the area and decanted the members of U2. Leonard himself turned up on foot, sharing vocal duties with Bono on a recording of one of his best known tracks Tower of Song. And after filming - there being no show to race off to - there was time to chat to fans who had been waiting patiently outside the club.

Cohen, 70, is a long time friend of the band and was at one of the early Vertigo shows in LA last month. In fact it was more than a decade ago that Bono recorded a spine-tingling version of his 'Hallelujah' on a Cohen tribute album, Tower of Song. The new documentary will also feature tributes from Jarvis Cocker and Nick Cave.