Zwölf Variationen in Es über „Zu Steffen sprach im

Sets of keyboard variations were extremely popular in the second half of the 18^th and the first half of the 19^th centuries. While some variations were written for teaching purposes, most of Mozart’s variations apparently originated as improvisations by which he displayed his brilliant keyboard technique, inventiveness, and imagination. The typical set of variations by Mozart is based on a preexisting melody and consists of 8 to 12, or rarely only 5 or 6, variations of increasing technical difficulty. In contrast, the themes of variations within a multi-movement work usually stem from Mozart himself; these sets rarely exceed 6 variations. Many of the independent works conclude with a variation in fast tempo, often in contrasting meter to the theme, which may be expanded with a coda evoking the impression of an improvisation. This final variation is usually preceded by a slow variation, often prepared by a variation using the parallel minor mode.