Charles Ives, Three Quarter-Tone Pieces, Mvt. II, Allegro, mm. 47-50
This example is a little march-like passage from the second movement, harmonized with A- and B-chords. I suspect that the A-natural in the last chord of measure 47 is meant to be a G-natural in order to form a correctly-spelled B-chord. Ives's handwriting was terrible and I wouldn't be surprised if his scores were plagued by transcription errors.