theme

…by having two or more themes embodying sharp contrasts of mood and shape, and further contrasted by means of texture, instrumentation, and harmonic colour. Alternation of dramatic and lyric moods, further, is most often characteristic of post-1750 chamber music.

A theme is a melody that is not necessarily complete in itself except when designed for a set of variations but is recognizable as a pregnant phrase or clause. A fugue subject is a theme; the expositions and episodes of a sonata are groups of themes.…

…larger whole is called a theme.

…might contain two clearly differentiated themes, but the stress is on continuity and on uniformity of musical texture rather than on contrast. In sonata form the emphasis is more dynamic; there is a stronger sense of contrast within the movement. The terms usually given the contrasting areas are “first subject/second…

…a number of stereotyped “theme families” can be distinguished. These furnished raw material for further development. In fact, composers’ originality found expression not so much in their original themes as in the realization of the implications of those themes later in the composition. Certain tunes are by nature not…