On a seemingly ordinary Thursday, at the time-honoured Glyndebourne opera festival, an unexpected interlude of protest emerged. In the sanctuary of the arts, amid the melody of Francis Poulenc’s Dialogues des Carmélites, a dissenting chorus brought the opera to a standstill. Sparked by the cause of Just Stop Oil, the interruption blended a traditional form of high culture with the pressing concerns of our era. This is the narrative of that day, a symphony of dissent resounding from the grand opera house to the streets of London.