I’ve always been a sucker for a good mix CD. Music has the power to transport us to another time and place, of nostalgia or wanderlust, and to place us in the culture of the music chosen. The exhibition “Paris en Chansons,” on view through July 29 at La Galerie des Bibliothèques, is like diving into the world’s greatest French mix CD—an astoundingly comprehensive collection of French music represented by songs about...