In ancient China, poetry in the ci form was actually lyrics composed to certain melodies. Its literary value gradually set it apart from music and became an independent form of literature.
Ci poetry became popular by Late Tang and the Five Dynasties with the emergence of famous ci poets like Wen Tingjun, Li Yu and others. The creation of ci poetry reached its height by the Song Dynasty, so influential that it was put on a par with Tang-dynasty poetry in the history of Chinese literature.
In the beginning, ci poetry was sung as entertainment. As compared with poems, the form of ci was more suitable for expressing sentimental and complicated sentiments such as vague feelings of grief, quiet leisure, and trivial meditation. It was sung in low voices over wine in hidden courtyards.
I ascend the stairs in prevailing chill
The dismal morning resembles autumn late
Painted screens display smoke and stream
Light as dream the flowers fall
Drizzle sprays as grief so light
A silver hook holds up the curtain fine
I compose a new song and drink a cup of wine
In the bower of last year when weather is as fine
When will you come back now the sun's on the decline
Deeply I sigh for the fallen flowers in vain
Vaguely I seem to know the swallows come again
Loitering on the garden path I alone remain
The Song Dynasty placed more importance on literary talents than on military feats. Scholars and officials, leading a comparatively easy life, were able to savor the subtle beauty of everyday life and put their gentle feelings into ci poetry.
Nevertheless, romantic themes of scenery and love were only one aspect of human life. When ci poetry became the vogue of literature, its range of themes gradually turned from small deep courtyards to extensive human life.
All aspects change on the frontier when autumn comes
Wild geese fly southward without faltering
Shouts echo on all sides along the border when the bugle blows
Amid a thousand mountains
In spreading mists and setting sun the lonely citadel is closed
A cup of poor wine my native land is far away
The Huns are not conquered
I have no intention to go home
The Tartar flute comes wailing over a land frost－bound
One can hardly sleep
The general is white-haired and soldiers shed tears
This is a poem written by Fan Zhongyan, a famous general of Northern Song at the borderland depicting the scenery and his feelings. Su Shi and Xin Qiji represented the heroic school that broadened the content of ci poetry, expressing their concern for their country and people and their optimism and enterprising spirit.

Listen not to the rain beating against trees

I'll walk at leisure and chant at ease
Better than a saddle
I like sandals and cane
I have no fear
In a straw cape
I'd spend my life in mist and rain
I am sobered by spring wind
Shrill and chill
And see the slanting sun atop the hill
Turning, I see the bleakness from where I came
Let me go back
To live a life without rain or shine