Ci originated in Sui and Tang Dynasties and prevailed in Song Dynasty. It is sung with music and irregular sentence patterns, also called "long and short sentences". Ci was originally sung with music, which is called "Quzi Ci". Later, Ci, like Yuefu poetry, gradually separated from music and became a different style of poetry, so some people called Ci "poetry". According to the number of words, words can be divided into Xiao Ling (less than 58 words), Middle Tone (59 words -90 words) and Long Tone (more than 9/kloc-0 words).