Abstract: In Book of History·The Canon of Yao,there are statements like “poetry is the expression of one's earnest thought and singing is the prolonged utterance of that expression.The notes accompany that utterance,and they are harmonized themselves by the pitch pipes”. They describe the situation of music being used in the rituals.The “earnest thought” embodies the purpose of the ritual itself,and has a relatively fixed religious will or emotion.In the Western Zhou Dynasty,the Ceremony of Entertainments and the Ceremony of Feasts were the secular rituals for guests.The “no-count-music” ritual of the Ceremony of Feasts made it possible for the idea that “poetry is the expression of one's earnest thought” to be separated from the ceremony and become a personal expression.During the Spring and Autumn period,the Ceremony of Entertainments and the Ceremony of Feasts were combined into one set of rituals,with “the Ceremony of Entertainments being held in the morning and the Ceremony of Feasts at night”,and after the Ceremony of Entertainments and the Ceremony of Feasts,there might be a separate Ceremony of Feasts again.For the purpose of entertaining the guests,the “main music” part of the Ceremony of Feasts was omitted,and only the “no-count-music” ritual was retained.The situation of “composing poems is to express one's earnest thought” all took place in the Ceremony of Feasts.Because of the ritual tradition,“composing poems to express one's earnest thought” has the characteristics of mysterious discourse.In order to overcome the obscurity,the phenomena like “interpreting the poem out of context”,the principle that “poems must be composed appropriately” and on-the-spot interpretation emerged,which weakened the ritualistic nature of “composing poems to express one's earnest thought” and promoted the flourishing of the secular discourse of “quoting poems to express one's earnest thought”.

Key words: “poetry expressing earnest thought”, the Ceremony of Entertainments and the Ceremony of Feasts, “poetry composition expressing earnest thought”, ritual discourse