The Tang poets excelled in wide-ranging imagery, gracious charm, broadness of conception and elegance of style. They would cultivate the spirit of a poem before setting writing brush to paper. By the Tang Dynasty a complete set of poetic genres had developed, and each genre had a full power of expression. The peak of the development of the theory of poetry in ancient China came in the Song Dynasty. In the categorized statistics in the Great Dictionary of Chinese Poetic Studies, edited by Fu Xuancong et al., there are over 200 theses on the various kinds of poetic genres. During the high tide of poetic and ballad creativity in the Tang Dynasty, and in the conditions of striving for a new direction for poetry and ballads in the Song Dynasty, fu poetry continued to thrive. In the Tang Dynasty the writing of fu poetry was widespread, and many writers of that time have left such works.