This study has two divisions: Part I, an historical and analytical summary of the emergence and development of the divertimento and the serenade in the eighteenth century, and Part II, the culmination of these structures in the works of W. A. Mozart. Two primary purposes are envisioned: 1) to further our knowledge of how German Gesellshafts-musik evolved toward its peak in the second half of the eighteenth century, and 2) to furnish a useful analytical handbook of Mozart's works in these genres.

This study is an attempt to shed some light on the treatment of one dissonance—the seventh—in the works of the following composers: Cipriano de Rore (1516-1565); Philippe de Monte (1521-1603); Giaches de Wert (1535-1596); Luca Marenzio (1553-1599); Carlo Gesualdo (ca. 1560-1613); and Claudio Monteverdi (1567-1643). The purpose of this thesis is to discover (1) the frequency of occurrence of primary (relatively accented) sevenths and their inversions (^ chords, etc.) in a selection of each composer's madrigals; and (2) the methods of handling sevenths employed by each composer, with particular emphasis on the relationship between these methods and sixteenth century theory.