Definition of Soata Form - Exposition and Transition

The opening of a Sonata Form can have an introduction and an has exposition material that establishes key and topic. It is then contrasted by transition material which sets up a modulation to V, frequently by modulation to V/V. A very concise example is found on the first page alone of Beethoven String Quartet #2 Op 18 #2 in G. It should be noted that there are numerous exceptions, but it is the conventional textures of exposition, and transition to the second key, and the contrast in the second key subject that satisfy the expectations of the form.

Second Subject and Close of Exposition

The material after the modulation is often a new subject with a contrasting melodic subject. Once the new key is established there is closing material and a cadence. In a Haydn Symphony this close often has a repeat sometimes with alternate endings for the repeat of the exposition and second subject (Second key area) and then for the beginning of the next section.

Development Section

An often complex development section follows, that contains the material most distant from the tonic tonality and is marked by the most invention harmonically and texturally with a wide variety of contrapuntal and thematic devices often involving the subjects of the exposition and second key. This is often the most profound section of the movement.

Cadence and Recapitulation