The Song Dynasty poem 'Qianqiu Nian' does not rhyme due to the unique characteristics of Chinese poetry and the rhyme schemes employed during the Song Dynasty. Unlike Western poetry, which often relies on end-rhyme, Chinese poetry traditionally emphasizes the harmony of sounds within a line, rather than at the end of lines. This is evident in 'Qianqiu Nian,' where the poem's structure and internal rhyme create a rhythmic flow that is distinct from the end-rhyme pattern commonly found in Western poetry.

The rhyme scheme in 'Qianqiu Nian' follows a pattern known as 'shi' in Chinese poetry, which involves the repetition of certain sounds within a line or a group of lines. This internal rhyme is a hallmark of classical Chinese poetry and is used to create a sense of continuity and musicality throughout the poem. The absence of end-rhyme in 'Qianqiu Nian' is a deliberate choice that reflects the poem's adherence to the 'shi' pattern.

Data from the Song Dynasty itself provides insight into the prevalence of this rhyme scheme. During the Song Dynasty, poetry was a prominent form of artistic expression, and the 'shi' pattern was widely used by poets. The 'shi' pattern allowed for a greater emphasis on the internal structure of the poem, which in turn allowed for more nuanced and expressive poetry. This is evident in 'Qianqiu Nian,' where the internal rhyme creates a sense of harmony and continuity that is absent in poems that rely solely on end-rhyme.

In conclusion, the Song Dynasty poem 'Qianqiu Nian' does not rhyme due to the unique characteristics of Chinese poetry and the rhyme schemes employed during the Song Dynasty. The internal rhyme pattern known as 'shi' creates a rhythmic flow that is distinct from the end-rhyme pattern commonly found in Western poetry, reflecting the emphasis on the internal structure and musicality of classical Chinese poetry.