Poems of the Han, Wei and Six Dynasties are generally called archaic poems, including ancient poems of Yuefu in the Han and Wei Dynasties, folk songs of Yuefu in the Southern and Northern Dynasties and literati poems in this period. Yuefu was originally the name of the official office. Yuefu songs are collected by Yuefu organs and sung with music scores. Later, the works written by copying the old theme of Yuefu or imitating Yuefu genre were also called Yuefu, although there was no soundtrack. In the mid-Tang Dynasty, Bai Juyi and others set off the new Yuefu movement, created new themes and wrote current events, so it was called the new Yuefu.