Several times in Frantz, director François Ozon’s requiem for post-World War I Europe, Philippe Rombi’s score returns to a refrain that sounds like a piano seeking out and nearly achieving the chords to “Ode to Joy,” the final movement of Beethoven’s Ninth Symphony. It’s a small gesture, but one that speaks to the deep-rooted unrest that keeps Frantz’s characters from finding any kind of solace.