Poetic songs were developed from the officially collected folk ballads and songs of the Han, Wei and Six Dynasties. They are characterized by great length, bold expression of feeling, diverse sentence patterns and laxity of the requirements of metrical forms. They followed the classic forms of five characters to a line, seven characters to a line and a mixed pattern in a flexible manner. This genre was established by Southern Dynasty poet Bao Zhao(414?-466) who drew inspiration from folk songs. Tang Dynasty poets Li Bai(701-762) and Bai Juyi(772-846) also wrote poems in such style.
- 放情长言，杂而无方者曰歌；步骤驰骋，疏而不滞者曰行；兼之者曰歌行。 （徐师曾《诗体明辨》） （尽情长咏，句式杂而不拘格律叫作“歌”；缓急自由，曲调稍缓但很流畅叫作“行”；二者兼而有之叫作“歌行”。）
Ge (歌 singing) refers to long chanting and offers lines of varying lengths unrestrained by metrical rules; xing (行 smooth-flowing) refers to chanting that freely and fluently accelerates or decelerates. If both ge and xing are involved, it is termed gexing (歌行 free and flowing chanting or poetic song).? (Xu Shizeng:?Interpreting the Different Types of Poetry)
- 歌行则放情长言，古诗则循守法度，故其句语格调亦不能同也。 （吴讷《文章辨体序说》） （歌行就是尽情长咏，古体诗则需要遵循一定规则，因此二者的句式、用语、体制、曲调也会有所不同。）
Gexing refers to chanting poetry in a free, flowing and unrestrained manner, as opposed to adhering meticulously to the standard guidelines of classic poetry. Thus, the sentence patterns, phrasing, metrical schemes and tonal effects of these two types of poetry end up being different to some extent.? (Wu Ne: Collected Prefaces for Different Types of Writing)