About Song, lines, quotations: (original) ... Song, line and quotation are three forms of ancient songs, which later became a genre of ancient poetry.
Gexing style: it is a variant of Yuefu poetry. After the Han and Wei Dynasties, there were quite a few Yuefu poems with the theme of "Song" and "Xing". Although the names are different, there is no strict difference between them. They all mean "Song". Their syllables and meter are generally free, and the form is the archaic form of five words, seven words and miscellaneous words, which is full of changes. Later, they had the style of "Gexing". In the Tang Dynasty, poets in the early Tang Dynasty created Yuefu poems, in addition to following the old themes of Yuefu in the Han, Wei and Six Dynasties, a few poets also created new themes. Although it was renamed Yuefu, it was not limited to temperament, so it was called New Yuefu. This kind of poetry has been greatly developed by Li Bai and Du Fu. For example, Du Fu's "Sad Chen Tao", "Mourning for the Head" and "One Car Paves Two Roads", as well as many of Bai Juyi's works, appear in the form of Yuefu songs, mostly mixed in a few words.