In a parallel period the two phrases are very similar. The first four measures of the second phrase in Bach's minuet are identical to those of the first. Measures 5 and 6 are also similar harmonically and melodically to measures 13 and 14. This is a parallel period:

In this other example. the phrases are even more similar:

Differences between the first and second phrase are shown in red. The first phrase ends with a half cadence and the second one with a perfect authentic cadence.

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