development

In music, the compositional process of extending and developing material. In particular, the term refers to the central process of sonata form, following the exposition, where thematic material is subjected to various developments, and the harmony undergoes more adventurous modulation than in the exposition or recapitulation, generally avoiding the tonic key before its reappearance in the recapitulation. The usual procedure is to develop the first or second subjects or both, but the procedure is by no means fixed and new matter may be introduced at will.