The middle part is comprehensive in nature, and the melody form of aria and recitation alternately depicts Mrs. Butterfly's deep yearning for happiness and her urgent and contradictory mood of looking forward to her husband's return. So the length is long and big, consisting of three paragraphs, and the tonality changes frequently.
The tonality of the reappearance section returns to the climax of the whole song, and the ending is composed of human voice and instrumental music, which are intertwined in the lyrics.
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