In Marseille, the sound of a civil defence siren is an “ordinary singularity”. This event is linked to men: those who hear the siren and those who make it ring. The GdRA applied its playful ethnography to this socio-technical device and the human relationships linked to it, revealing the results in an outdoor artistic performance combining narrative, “living” portraits, text and music. The audience thus heard of such things as Marseille’s electric engineering experts, suffocated hens, community crèche, the emergency population-warning network, local grievances, Memo no.456 of September 1, 1964, the NT 3 machine and its kW power, in short, of the daily grind of these men and their siren. But are we going to hear of Mr I?