In a rehearsal room in Hackney in east London, a dozen musicians from Egypt, Jordan, Morocco, Syria, Tunisia and Lebanon are in full swing. "You are my Arabian desert," sings Ruba Saqr in Arabic, strumming the outsize guitar on her lap, "you are my sand dunes. How am I going to love when you are gone?" Moslem Rahal, leaning casually against the wall of the tiny stage, fills the gaps with snorts and flutters on the ney flute. The song ends with Saqr and Hiba Mansour chanting the chorus over and over again, before all the musicians stop abruptly. There is a moment of magical silence.

"Sorry," says Leo Taylor, the drummer. "I mucked up the opening."