主题变奏曲

тема с вариациями

把同一音乐主题写成变奏曲

варьировать музыкальную тему

这首歌像是一个熟悉的旧曲调的变奏曲

The song sound like a variation of a very old and familiar tune.

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

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.