What is the french song in Family Vacation starring Chevy Chase when museum?

The French song playing in the museum scene of "National Lampoon's Vacation" (not "Family Vacation") is "Clair de Lune" by Claude Debussy.

This iconic piece of classical music is known for its dreamy and melancholic mood, which perfectly complements the scene where Clark Griswold (Chevy Chase) tries to impress his family with his "knowledge" of art and history.