This film is the perfect example of picture working against soundtrack to highlight and define one another. An ideal Alienation Effect (opposed to gesamkunstwerk).
Of course, the soundtrack was completed before the animation was begun. Tissa David, who animated this (read Michael's post -it's great) once asked Hubley the same question I asked her. "How do you know the soundtrack will work if you record it all beforehand?"
His response: "If the music works and is good, the picture will work and be good." And there we have a secret from the gods.