Section 13.2 The Sentence
A sentence in music is a phrase with a specific melodic construction: a melodic idea (motive 1 or subphrase a) is either repeated or sequenced then followed by either related or unrelated material leading to a cadence.
In this first example, Mozart sequences motive 1 from measure 1 up a step in measure 2. Measure 3 contains related material and measure 4 contains cadential material.
In the next example, Beethoven changes the intervals of subphrase a in measures 3–4 to fit the dominant harmony. He extracts motive 2 from subphrases a and a’ in measures 5–6. Measures 7–8 lead to a half cadence.
In the next example, unrelated material follows subphrase a and its repetition.