Meaning Discrimination of Yuefu Poems in Southern Dynasties

Yuefu was a name of music government office at first,and between Song and Qi in Southern Dynasties it had been changed into the name of a type of writing. But the literary critics in Southern Dynasties had different views for Yuefu's classfication,because some of them emphasized its music quality,and others literature.From this we can see clearly their literary concept,especially the concept of the discrimination of the type of writing.