The fire of 15 April 2019 imperilled the heritage of Notre-Dame Cathedral in Paris, built up over nine centuries of history. An architectural patrimony that belongs to all humanity. Over the centuries, painting, literature, photography, film and music have further enriched its place in our collective imagination. From the end of the twelfth century, the Notre-Dame School developed a sophisticated style that left its mark throughout Europe. The Mass of Guillaume de Machaut, dedicated to the Virgin Mary, was influenced by it. This work is one of the musical jewels left to us by the fourteenth century.