Sung visits, the tenor lecturer Grégoire Ichou has the secret. He mixes his historical and artistic explanations with musical excerpts that he interprets (opera arias, popular songs, French melodies, etc.) in order to weave links that can be thematic, formal, chronological, biographical or aesthetic. From Saint-Saëns to Poulenc, from Napoleon to Picasso, travel through all the different spaces of the Theater and discover the Châtelet and its history through music.