The great organ in Notre-Dame Cathedral in Paris is as magnificent as it is historically significant. Though preserved from the flames and water during the fire that engulfed the cathedral's roof in 2019, the instrument was taken apart, then carefully reconstructed and tuned. Olivier Latry, titular organist of Notre-Dame Cathedral, and Bach expert Thierry van Bastelaer discuss the history of the organ, the factors that make it unique, and the impact of the cathedral’s restoration on its sounds.