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Section 24.8 Distinguishing between Rounded Binary and Ternary

In homework and on the test, you will encounter pieces that are five or six phrases long that could be rounded binary or ternary. While other authors have their own means to differentiate rounded binary from ternary, this text offers the following criteria to consider:

  1. Proportion: consider the proportion of the contrasting section to the other sections. If the contrasting section is too small to stand alone, the form is more likely to be rounded binary.

  2. Nature: consider the nature of the contrasting section.

    1. If the melody is built from motives from the first section, the form is likely to be a rounded binary. Ternary form will have a contrasting melody in the contrasting section.

    2. If the harmony consists mostly of a dominant pedal, or a V chord alternating with a I or I\(\left.\text{}^{6}_{4}\right.\) chord, the form is likely to be a rounded binary.

  3. Era: consider the era when the piece was written. A piece by a Baroque composer (J.S. Bach, Handel, Scarlatti, Couperin) or Classical composer (Haydn, Mozart, and Beethoven) is more likely to be in rounded binary form, whereas a piece by a Romantic era composer (Schubert, Schumann, Chopin, Mendelssohn, and Brahms, among others) is more likely to be in ternary form. Note that these are generalities. Baroque and Classical composers will write compositions in ternary form and Romantic composers will write pieces in rounded binary form.

Consider the following piece by Beethoven:

Figure 24.8.1 Beethoven, Eleven Bagatelles, Op. 119, No. 9

In terms of proportion, bars 9–12 contain contrasting material to bars 1–8. Because the contrasting material lasts for half as long as the open section, we consider the proportion as pointing toward rounded binary.

In terms of the nature of the contrasting section, the melody is built from the contour of the first four notes of the first measure, and the harmony alternates between V and I\(\left.\text{}^{6}_{4}\right.\). Both the harmony and melody point us in the direction of rounded binary.

Finally, consider the era in which Beethoven lived. Is he considered a Classical or Romantic composer? This is a difficult question to answer, as Beethoven is a unique figure who is a bridge between the Classical and Romantic eras. However, it’s generally safe to consider Beethoven as belonging to the Classical era, and therefore as likely to write a rounded binary form.

You will encounter examples on homework and the test where these three criteria are not unanimous and you will have to weigh the evidence to come to a conclusion.

Subsection 24.8.1 Written–Out Repeats

Occasionally you will encounter an example where the repeats are written out. When you encounter such a piece, put the repeats in your diagram even though there are not in the score.