MUS 312 Form & Analysis

G. The Binary Principle:  Sonata-Allegro Form

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The expansion of formal components associated with rounded binary movements eventually produced a stylized procedure known as sonata-allegro form.  While such forms are generally longer than rounded binary structures, tonal and structural elements of the binary principle are reflected constantly.

Expanded Rounded Binary Form

  1. In the shorter simple and rounded binary movements, an authentic cadence in the dominant signals the conclusion of part A.

  1. The return to the tonic in Part B is a typical binary procedure.  In the less complex designs, all the thematic material in Part A is usually derived from the opening few measures.

Sonata-Allegro Form

EXPOSITION--serves to expose or state the material upon which the entire movement is based.

  1. Theme 1:  stated in the tonic key; provides stability, frame of reference for following sections.
  1. (Theme Group 1):  sometimes Theme 1 is not a single melody, but a group of melodic ideas that form a first theme group.
  1. Transition: prepares for the second theme (or group), traditionally in a related key.  May contain:
  • First theme (group) material--fragments
  • Second theme (group) material--intro to what is to come
  • Combination of first or second theme (group) material
  • Material unrelated to either theme (group).
  1. Theme 2:  customarily contrasts with the first; if Theme 1 is assertive, Theme 2 may be quiet and lyrical.
  1. (Theme Group 2):  in the late Classical & Romantic periods, the second theme is often found as a theme group.
  1. (Monothematic):  in the early Classical period, some sonatas contain only one theme; the second theme is simply the first theme transposed.
  1. Major keys:  in major, the second theme is most often in the dominant key.
  1. Minor keys:  in minor, the second theme may be in the relative major or dominant minor (v is rare).
  1. Theme 3:  sonata forms of extended length may contain a third theme (closing theme); this theme is usually in the same key as the second theme.
  1. Codetta:  (optional) completes the exposition; may or may not recall first theme material has characteristics of an extended cadence--not lengthy.

DEVELOPMENT--provides an opportunity for motivic development of material presented in the exposition.

  1. Characteristics:  restless, constant change, virtually any key area is a possibility.
  1. Techniques:  sequence, modulation, augmentation, diminution, change of mode, fragmentation.
  1. Form:  no conventional organization, but most can be divided into identifiable sections based on thematic material.
  1. Retransition:  final section of development which prepares for recapitulation in tonic key; usually combines fragments of first theme.

RECAPITULATION--return of original themes, all at the tonic level; provides a balance to the entire movement.

  1. Exception to tonic return:  in some early sonatas, the recap begins in the subdominant and is a virtual transposition of the exposition.
  1. Return of Transition:  in the recap, the transition loses some of its reason for being because it does not support a modulation, i.e., it may not be present; if a key change occurs (the exception), a return to the tonic causes the transition to be longer than in the exposition.
  1. Return of Theme 2:
  • In major:  tonic key.
  • In minor:  tonic, sometimes parallel major.
  1. Return of Theme 3:  tonic key; however, if Theme 2 appears in the parallel major, Theme 3 may follow suit.
  1. Codetta:  if there is a codetta, it will appear in the tonic key.

General outline of Sonata form (there are many exceptions):



Theme 1 (group) / Transition I / i Expository / Transitional
  I - V / i - III  
Theme 2 (group) V (in major) / III (in minor) Expository
Theme 3 (opt.) V (in major) / III (in minor) Expository
Codetta (opt.) V (in major) / III (in minor) Terminative


One/more themes developed Various keys Transitional / Developmental


Theme 1 (group) / Transition I / i Expository / Transitional
  (no modulation, or return to tonic)
Theme 2 (group) I / i Expository / Terminative
Theme 3 I / i Expository / Terminative
Codetta (opt.) I / i Terminative

Optional Sections:  Introduction / Coda

  1. Introduction--the exposition may be preceded by an introduction.
  1. Coda--the recap may be followed by a coda which refers to units found in the exposition.
  1. Sonatina--short movement in sonata form; main structural units are present.

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