乐府诗的主旨并非如古人所言,仅仅取决于本事或古辞,民俗文化对乐府诗主旨的形成、传承、变异也有举足轻重的影响。本事非止一端且存在矛盾时,主人公的身份、故事情节等方面与民俗文化契合度高的本事,往往成为大多数诗人创作之依据。既无本事亦无古辞的乐府诗,主旨也可能相当集中,在其中起凝聚作用的,往往是与乐曲来历有关的民俗文化。因题命辞的创作方式,使得诗人常常会从曲名所蕴涵的或能够涉及的民俗内涵里衍生出新的主旨。与乐府诗演唱关系密切的民俗活动也有可能导致乐府诗主旨的变异。 The main theme of Yuefu poetry is not as the ancients said, only depends on the ability or the ancient Ci, folk culture has the decisive influence on the formation, inheritance and variation of the theme of Yuefu poetry. When there is more than one skill and there are contradictions, the ability of the protagonist's identity, storyline and other aspects that fit well with folk culture often becomes the basis for the creation of most poets. The Yuefu poetry, which has neither the skill nor the ancient speech, may also have a central theme, and the cohesive role in it is often the folk culture related to the origins of the music. Due to the way of creation of the subject and the rhetoric, the poet often derives a new theme from the connotation of the folklore implicated or can be involved in the title. The folk activities closely related to Yuefu poetry singing may also lead to the variation of the theme of Yuefu poetry.