This passage would be harmonized primarily with alternating V and i as shown below. However, while V is the "correct" harmonization of the A octaves, it ruins the effect. Part of what makes this passage so effective is the harmonic ambiguity of the A octave.

This passage would be harmonized primarily with alternating V and i as shown below. However, while V is the "correct" harmonization of the A octaves, it ruins the effect. Part of what makes this passage so effective is the harmonic ambiguity of the A octave.