China's earliest poetic genres formed in direct relationship with music, and pentasyllabic shi poetry is no exception. This was a new poetic genre that formed after tetrasyllabic poetry and the sao style associated with the Chuci 楚辭 (Lyrics of Chu), and it represented a breakthrough in the formal development of Chinese poetic genres. The lines of shi poetry are made up of a “balanced foot” and an “unbalanced foot,” with the balanced foot in the front and the unbalanced foot following behind. Pentasyllabic shi poetry flourished during the Han dynasty, and its development was driven forward by the exploration of the musical and rhythmic properties of the Chinese language in poetic form. Given that Chinese classical poetry was born from music, the sound and rhythm of poetry are of great importance. Chinese is a monosyllabic language in which each graph has just one syllable. Ideally, a line of poetry must maintain two properties: first, to express the semantic meaning of each single monosyllabic word and, second, to allow for the free combination of monosyllabic words. Pentasyllabic shi poetry is a form precisely suited to fulfill these two conditions. In the initial stage of its development, poets focused primarily on the balance in the foot of each line and the balance within poetic lines. Later they focused increasingly on balance in the combination of monosyllabic words and in the parallel arrangement of lines in couplets. The fact that pentasyllabic shi poetry ultimately moved toward greater tonal regulation similarly is due in large part to greater attention to the role of musical rhythm.