How did Parisians respond the day they saw their beloved Notre-Dame engulfed in flames? They sang. Believers and non-believers huddled together on the Île Saint-Louis after nightfall on the second day of Holy Week, hoping for a miracle; a vigil such as Paris had never seen, fuelled by the collective fear that a central piece of its history might be reduced to ash in the morning.

For hours, we sang. Ave Marias and Hosannas in canon, Marian hymns, the rousing anthem La Première en Chemin Marie, drifted along the Seine; music that would have been heard in the cathedral. I knew none of the French tunes but their simplicity and urgency buoyed me along through the crowd. I was reminded of my first Christmas alone in the city of light; though not religious, I was drawn to Notre-Dame and sang Douce Nuit there for midnight mass, becoming part of the living history of the place, if only for a few minutes.

Apart from the flickering glow that had been largely contained, glimpsed through the gushing streams of an immense fire hose, the eastern façade with...