By the end of the first half an hour, the burly Egyptian journalist next to me was in tears. By the end of the show, the entire Barbican audience was on its feet. It was a memorable evening – even if the august Barbican Hall was nothing like the teeming masses of the Tahrir Square at the height of the protests against Mubarak. One thing was clear though – those who think popular music has lost the power to change things and mutated into mere consumerist spectacle will have to eat their words. Especially if they understand Arabic.