Large-Scale Structure

Formal Organization

Large-scale structure within Western classical music has traditionally been conceived of as a hierarchical assembly of gradually larger musical segments, with lines of division drawn to reinforce the completion of a melodic, rhythmic, or harmonic idea. Sequences of musical notes combine to create phrases, and individual musical phrases are combined to create larger musical sections, which in turn combine to create the entire composition or a single movement of a longer multimovement work. Structural sections are labeled during the act of music analysis by considering the repetition and modification of material in conjunction with tonal movement, and the overall framework of the identified sections is often discussed with relation to several standard formal structures.

Binary form is defined as a musical structure containing two sections, both of which may be repeated before proceeding to the next section, with a movement away from the original tonal center during the first section and a return to the original tonal center during the second. A piece in ternary form contains three major divisions: a first section, a contrasting second section, and a return of the first section. This is similar to a rondo form, which includes multiple returns to an initial section, interspersed with a number of differing secondary sections. Many compositions employ a variation form: a structure comprising an initial musical theme and any number of variations created by modifying the melodic, harmonic, or rhythmic content of the theme.

The most well-known scheme for large-scale structure in music during the 18th, 19th, and 20th centuries is the sonata form. A composition or single movement written in sonata form will begin with the exposition, wherein the initial musical themes are stated. This exposition is typically divided into two subsections, with the second section located in a secondary tonal center. The exposition is followed by a development section, wherein themes from the exposition are subjected to various developmental modifications. The piece concludes with a recapitulation section, restating material from the exposition within the original tonal center.

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