Whereas Chapter 4 provides an overview of individual quartets, this chapter offers particular theoretical perspectives on selected movements, or sections of movements, drawing upon eighteenth-century theories of rhetoric and topicality.

Mozart himself wrote no textbooks, nor is he known to have subscribed to any one particular branch of the theoretical investigation of music. His father, however, maintained a keen interest in theoretical issues and owned a number of textbooks by Fux, Mattheson and Riepel. He even told Mozart that he intended one day to write a theoretical work of his own. It is unlikely that Mozart was ignorant of eighteenth-century music theory, however silent he remained about it in his correspondence.

The objectives of this chapter are to illustrate some ways in which Mozart's quartets might have been appreciated by late eighteenth-century musicians within some prevailing theoretical frameworks; and to allow for more extensive treatment of some aspects of individual movements than is possible or appropriate in the preceding synopsis.

Rhetorical approaches

The belief that musical form was analogous to rhetoric was by no means uncommon during the eighteenth century. Johann Nikolaus Forkel applied the accepted divisions of an oration to the analysis of musical form as follows: