Binary form

A piece is in binary form if it has two large sections. When creating form diagrams, we will represent large sections with uppercase letters, in contrast to phrases, which we represent with lowercase letters. Figure 34-1 represents a typical manifestation of binary form where the second large section (B) presents contrasting elements to the first large section (A). It shows a modulation to a new key and back to tonic, which often occurs in binary form but is not required.

Sometimes binary form is referred to a two-reprise form when repeat signs demarcate each section, as shown in Figure 34‑2. Although not always present, repeat signs and double bar lines can often be important visual cues to understanding the formal design of a piece.

Pieces in binary form can manifest in many different ways depending on their tonal content, presence of restated material, and length of sections. Special terminology, appearing in the descriptions below, helps us make sense of different manifestations of binary form.

Tonal content. If the A section of a binary piece can stand on its own harmonically, then it is sectional. To be sectional, the A section must end with a conclusive cadence (either IAC or PAC) in the tonic key. If the A section ends with an inconclusive cadence (such as a HC), or if it ends in a different key (even if there is a conclusive cadence in the new key), the form is considered continuous.

Presence of restated material. If no material from the A section reappears in the B section, the form is simple binary. If a portion of the A section returns at the end of the B section, the form is rounded binary. Figure 34‑3 shows a typical representation of rounded binary. In this design, we still perceive two large overarching contrasting sections, as demarcated by the repeat signs and ending double bar line, but the large B section ends with A”.

A common example of rounded binary is 32-bar song form, which can be represented as in Figure 34‑4. In this form, the B section is referred to as the bridge.

Balanced binary forms offer another, but less common way of restating material. A technique found in some Baroque dance movements, balanced binary forms occur in continuous pieces when a brief portion of the end of the A section (usually stated in the key of the dominant) is restated at the end of the B section in the tonic key.

Length of sections. Binary forms are considered symmetrical when both sections are the same, or nearly the same, length. When one section (usually B) is longer than the other, the form is considered asymmetrical.

Elements of unity and contrast

Suggestion: Musicologist Jan LaRue’s book Guidelines for Style Analysis provides a detailed method for considering elements of unity and contrast when approaching analysis of form design.^[1] Some of the elements listed in LaRue’s categories of “sound,” “harmony,” “melody,” and “rhythm,” summarized in Figure 34-5, are the most relevant to our analytic approach to form. You can use the list in Figure 34-5 as a checklist of things to consider that may contribute to the perception of unity and contrast between large sections.

Cues for analysis

Whenever you encounter a new piece that appears to be in two large parts, consider the questions in Figure 34‑6, which can guide and inform your analysis.

Pieces for analysis

Let’s consider some of the questions in Figure 34‑6 as they apply to the movement reproduced in Example 34‑1. After listening to this movement, we can identify that it begins and ends in F major. It features a modulation to C major (a closely related key) prior to the point of bisection (m. 9), and thus the form is continuous. No material from the A section recurs within the B section, so the form is considered simple. Its form is also considered a two-reprise form, as both sections use repeat signs to help delineate the form.

In contrast, Example 34‑2 does not modulate and is entirely diatonic in the key of C major. Because it ends with tonic harmony in the tonic key before the point of bisection (there is an implied authentic cadence in mm. 7–8), it is a sectional form. The opening melody is restated at the end of the B section (compare the material starting at m. 1 and m. 17), creating a rounded binary form. Like most rounded binary forms, this movement is also asymmetrical to account for the additional return of the opening material. The two-reprise structure of Example 34‑2 allows listeners to perceive it in two distinct parts, in spite of the rounded asymmetrical design. Figure 34‑7 provides a diagram summarizing the formal and harmonic features of this theme.

Example 34‑3 is an example of 32-bar song form, which is both rounded (mm. 1–8 are restated following the bridge section) and continuous (there is an implied half cadence before the point of bisection). When a musician performs the repeats, we hear the form as represented in Figure 34‑8.