Would War and Peace be improved with added period details like the actual song Natasha was singing? I would argue not. That feeling of Andrei’s of the “infinitely great and illimitable within him” is the same thing that he saw in the sky. It’s also what Kant called the sublime ( a separate category from the beautiful), and it’s part of everybody’s experience of being alive. Trying to pin it down to a specific cultural fact might make it harder to see the universality of this moment.