Exposition

In sonata form, the exposition is the first statement of the theme; it is the first of the three major sections in sonata form. Usually there are two major theme groups in the exposition, possibly followed by a codetta. The exposition is followed by the development, in which the themes presented in the exposition are expanded, reshaped, and manipulated. Finally the same themes are presented in very nearly their original form in the recapitulation, which is the last section of the sonata form.the first occurrence of the theme or subject in a work, where the principal idea of the piece is stated