Because that world's gone. The world where people walked around whistling that music. All the madrigal singers in the world can't make that other one real again. It's like dinosaurs. We can put them back together perfectly, bone for bone, but we don't know what they smelled like, what kind of sounds they made, or how big they really looked standing in the grass under all those fossil fern trees. Even the sunlight must have been different, and the wind. What can bones tell you about a kind of wind that doesn't blow anymore?