Exposure (music)

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In music, exposition (lat. Exponere to emphasize ) describes the part of a composition in which the topics are presented for the first time.

In the fugue , the term stands for the fact that the topic is presented and guided by all voices.

The exposure of the classical sonata form usually consists of the “ main movement ” (with the first theme), the side movement (with the second theme) and the final group (thematically structured passage work). According to the rules of the Wiener Classical the first subject is always a dynamic, which in the key of the tonic is presented, where a second, lyrical theme (for the major -Tonarten in the dominant key , wherein the minor keys in relative key is opposed) .

In the 19th century the sonata main movement developed further, which allowed a departure from the strict form of the composition. Both the rule of the structure of the sonata main movement and that of the compelling juxtaposition of a dynamic and a lyrical theme were increasingly broken. Examples of this are:

  • the eighth symphony in B minor ( The Unfinished ) by Franz Schubert : Here, contrary to custom, the two themes are both presented in piano in the exposition and they are also very similar in character
  • The Piano Concerto No. 1 in B flat minor by Pyotr Ilyich Tchaikovsky : At the beginning of the work, it is not the first theme that takes up a lot of space, but an introductory theme in D flat major
  • The Piano Concerto No. 1 in E minor by Frédéric Chopin , in which three themes (introduction and first theme in E minor, second theme in G major) are presented in the first movement and only the introductory theme is dealt with in the development

The structure of an exposition in sonata form

After the first topic has been introduced, there is a modulation , that is, a key change. This key transition serves the second theme, which then appears in a contrasting key and which is in the dominant of the basic key. This is often followed by a final group with which the exposure ends. Sometimes the exposure is repeated. In front of it there can be a (slower) introduction. This is followed by an implementation , a recapitulation and sometimes a coda .

For the harmonic relationships of keys see also: Harmony , Circle of Fifths .