Variations, which often use borrowed material, fall into the following seven historical categories: (1) Renaissance and Baroque variations on secular songs, dances, and arias; (2) Renaissance and Baroque variations on plainchant and chorales; (3) the Baroque basso ostinato variation; (4) the ornamental variation of the eighteenth and nineteenth centuries; (5) the nineteenth-century character variation; (6) the nineteenth-century basso ostinato variation; and (7) the free variation of the late nineteenth and early twentieth centuries. Variations also fall into two basic plans, structural and free. Variations in categories (1) through (6) above followed the older structural plan, in which basic relationships of parts, sections, and phrases in the theme were preserved in the variations. By the early twentieth century, variations were constructed in two ways: following the structural plan and following the newer free plan, in which basic relationships of sections and phrases in the theme were disregarded. Generally, the most conspicuous elements of themes most emphatically demand change. Rhythm is the most conspicuous element, and thus must be varied the most. The melodic subject is second most conspicuous. The harmonico-structural frame is least conspicuous, was historically generally retained, and therefore may be considered as the substance of the theme. All variations are committed to the task of securing unity within a manifold. In the nineteenth and twentieth centuries there was a growing trend toward the use of original themes. Renaissance and Baroque themes were frequently borrowed from dances and secular songs. In the ornamental variation, borrowed themes continued to include the dance piece and the popular song and also included the operatic excerpt. In the nineteenth-century character variation, neither the secular song nor the operatic aria were important sources of borrowed themes. Instead, composers used instrumental works (such as suites and sonatas) and instrumentally conceived themes from members of their own circles. Despite the trend toward the use of original themes, borrowed themes, including folk songs, still persisted in the free variation.

Index Classifications: General, 1500s, 1600s, 1700s, 1800s, 1900s

Contributed by: Daniel Bertram