A form that is an altered version of a given theme, diverging from it by melodic ornamentation and by changes in harmony, rhythm, or key. 变奏曲一种给定主旋律的改编版,通过旋律的修饰和节奏或琴键的变化而从中分离出来
The figure formed by two planes diverging from a common line. 平面角从一条公共直线出发的两个平面形成的图形