Expansions make a phrase last longer than expected. They can be internal (between the beginning and ending of the phrase) or external (before the beginning or after the end).

Internal expansion techniques include repetition, stretching, one-more-time technique, and alternative path.

External expansions fall into two categories:

Prefixes occur before the beginning, such as an introduction.

Suffixes occur after the cadence, such as post-cadential extensions, codettas, and codas.

Contractions make a phrase shorter than expected.

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The terms expansion and contraction refer to ways composers play with the expected length of a phrase.

What does "expected length" mean?

When a phrase invokes one of the archetypes without following it exactly, we can often identify how long a closer representation of that archetype would have been.

Sometimes the cadential motion of the phrase allows us to anticipate where a cadence might occur, but the phrase evades the expected cadence.

Sometimes a piece states two versions of a phrase—one unexpanded and the other expanded—giving us a model to which we can compare the expanded version.

Expansion refers to the process of making a phrase longer than we expect. This lengthening might occur within the phrase ("internal expansion") or outside of the phrase ("external expansion"). Contraction refers to the process of making a phrase shorter than we expect, and it always occurs within a phrase.

In this chapter, we offer an overview of several techniques for phrase expansion and contraction. This isn't an exhaustive list, but it covers several of the more common techniques. The terminology concerning expansion and contraction techniques can quickly become overwhelming. What's most important is to be able to recognize when a phrase is longer or shorter than expected and to be able to describe what's creating the difference in length.

Internal Expansions

The four techniques we discuss below—repetition, stretching, one-more-time, and alternative path—all occur within a phrase: after the phrase's beginning, but before its cadence. Often, composers use these techniques in combination; in fact, it's relatively rare to find a phrase that's expanded using only one technique.

Repetition

[](https://viva.pressbooks.pub/app/uploads/sites/12/2019/07/Example_001_Repetition_Sheldon_Bright_Lights.png) Example 1. Internal expansion via exact repetition in Robert Sheldon's Bright Lights! (0:49–1:03).

Sometimes when a composer repeats material, the repetition creates extra length.

Example 1 shows an exact repetition of a motive within a unit that creates extra length: a four-measure antecedent is followed by an expanded five-measure consequent. The extra length results from a repeated motive within a unit.

[](https://viva.pressbooks.pub/app/uploads/sites/12/2021/06/combined-Example_002b_Repetition_Mozart_447-3.png) Example 2. Internal expansion via varied repetition in Mozart's Horn Concerto, K. 447, I, mm. 1–9 (0:00–0:18).

Example 2 shows a varied repetition in which a whole unit is repeated to add extra length: a four-measure compound basic idea (c.b.i.) is followed by a five-measure continuation. The continuation begins with a sequence that expands it from the expected four measures to five.

Not all repetitions create expansion! Be careful to differentiate expansion-creating repetitions, which are unexpected, from more predictable repetitions, such as when the basic idea is repeated in a presentation.

Stretching

[](https://viva.pressbooks.pub/app/uploads/sites/12/2019/07/Example_003a_Stretching_Schubert_459.png) Example 3. Internal expansion via stretching in Schubert's Piano Sonata D. 459, I, mm. 1–9 (0:00–0:17).

Sometimes composers will lengthen a harmony or melody by increasing its duration so that it lasts longer than expected. When that happens, we say that the unit that contains the harmony or melody has been stretched. In Example 3, a four-measure presentation is followed by a five-measure continuation. The continuation's cadential idea is stretched when a \mathrm{I}^6 chord and the cadential dominant (embellished by a \mathrm{Ger}^6 and a cadential ^6_4) each last for a full measure as opposed to both occurring within a single measure.

One-More-Time Technique (o.m.t.)

Coined by Janet Schmalfeldt (1989), the one-more-time technique involves three steps: 1) the music tries to cadence, 2) the attempted cadence is evaded, and 3) the music retries the cadence. The re-tried cadence often uses the same material, such that it feels like the music is "backing up," but it may also retry the cadence with different cadential material.

[](https://viva.pressbooks.pub/app/uploads/sites/12/2019/07/Slide5-6.png) Example 4. Internal expansion via the one-more-time technique in Mendelssohn, Op. 8, no. 5, "Pilgerspruch" (0:00–0:37).

In Example 4, a cadence is proposed in m. 10, but it's evaded (\mathrm{cad^6_4 – V^4_2 – I^6}). A one-more-time repetition of the cadential idea ensues. The one-more-time unit is stretched: notice that it takes two measures (compared to one originally) for the melody to descend C–B♭–A–G, and it takes a full measure (compared to a half measure originally) for the cadential \mathrm{^6_4} to resolve to \mathrm{V}^7.

Alternative Paths

An alternative path occurs when unexpected new material either temporarily or permanently causes a phrase to deviate from its expected trajectory toward a cadence. A temporary deviation is called a detour. Detours return to previous material from within the phrase before the phrase achieves a cadence. A permanent deviation is called a reroute. Reroutes achieve cadences