The aria is from La Wally and is performed by Wilhelmenia Wiggins Fernandez, who is the object of obsession and affection of the film's center, Jules. Later in the film, he and the Diva take a walk around Paris accompanied by the spare, Satie-like tune "Sentimental Walk" by the soundtrack's composer, Vladimir Cosma.
Absolutely gorgeous throughout and wonderfully spare in dialogue, letting the camera and music tell much of the story and emotion.