Ci (Lyric Poetry) is a new form of poetry that sprung up in the Tang Dynasty (618-907) and Five Dynasties Period (907-979), which can be performed with music.

Chinese music experienced significant changes in the Sui and Tang dynasties (581-907). With communication of politics, military affairs, business, missionaries and culture, etc., foreign and ethnical music was introduced to the Central Plains in great quantity, which was not only popular among ordinary people, but also in the upper class and palace. It gradually blended with Chinese traditional music of the Han nationality, which gave birth to Yanyue (referring generally to all music and dances entertaining banquets). Also known as Popular Music, Yanyue was the most widespread and popular music with great vitality compared with Yayue (Elegant Music). There were 222 melodies of Yanyue played with lyrics at dinnertime in the Tang Dynasty. The length of every line of the lyrics varied with the change of rhythms of the melody and these lyrics were the proper form of Ci (Lyric Poetry).

There are many tonal patterns and rhyme schemes of Ci poetry. A book in the Qing Dynasty (1644-1911) collected 660 tonal patterns. With successive additions, there are more than 1,000 tonal patterns in total, but among them only about 100 are frequently used.

Quzici in the Tang Dynasty first prevailed among ordinary people, but the literati began to compose the Lyric Poetry for music since the mid Tang Dynasty. Ci at that time had to be in line with strict rules of both tonal patterns of the music and rhymes of the poetry. From the Song Dynasty (960-1279), a lot of Ci composers were not specialized in music, and thus they composed Ci only in accordance with rules and forms of poems. Therefore, Ci gradually could not be played with music, and became an important form of Chinese traditional poetry.