A melody or theme is a rational progression of single tones. Here is the melody or theme with which Beethoven begins the familiar “Moonlight Sonata”:
Beethoven’s “Moonlight Sonata”
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It is a melody, but it does not constitute harmony, for harmony is the rational combination of several tones, as distinguished from the rational progression of single tones which constitute melody. But when Beethoven adds an accompaniment to his theme and it becomes:
Beethoven’s “Moonlight Sonata”
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