[Illustration: Example 46. Fragment of Mozart.]
Here, again, the condition of Unity prevails, but with a still greater infusion of Variety; the melody of the Consequent phrase resembles that of the Antecedent in every detail; the rhythm is identical, and it is evident that the second phrase is designed to balance the first, figure for figure, the principal change being that some of the figures are simply turned upside down (compare the places marked N. B.). The semicadence rests upon a dominant chord (fifth-step) of D major; the perfect cadence upon the same chord, it is true, but as tonic harmony of A major, with keynote in the extreme parts. Being a keynote, though not in the original key, it is valid as perfect cadence.
Further (Beethoven, pianoforte sonata, op. 13):—
