And those who were seen dancing were thought to be insane by those who could not hear the music.
— Friedrich Nietzsche

Silent Disco – Wikipedia

PARIS (AP) – Thousands of Parisians danced in eerie silence at the Gare du Nord train station and galleries left their doors open all night for the French capital’s annual “Sleepless Night” festival. At the train station, twelve DJs performed for crowds wearing headphones at a special “silent disco” event from Saturday to Sunday. The party-goers could choose from three different music channels, dancing to their own rhythms.

Washington Times