Tang poetry () refers to poetry written in or around the time of or in the characteristic style of China's Tang dynasty, (June 18, 618 – June 4, 907, including the 690–705 reign of Wu Zetian) and/or follows a certain style, often considered as the Golden Age of Chinese poetry. The Quan Tangshi includes over 48,900 poems written by over 2,200 authors. During the Tang dynasty, poetry continued to be an important part of social life at all levels of society. Scholars were required to master poetry for the civil service exams, but the art was theoretically available to everyone. This led to a large record of poetry and poets, a partial record of which survives today. The two most famous poets of the period were Li Bai and Du Fu. The Qing dynasty selection,Three Hundred Tang Poems, has made Tang poetry familiar to educated Chinese in modern times. The periodization scheme employed in this article is the one detailed by the Ming dynasty scholar Gao Bing (1350–1423) in the preface to his work Tangshi Pinhui, which has enjoyed broad acceptance since his time. This system, which unambiguously treats poetry composed during the reign of Emperor Xuanzong (the "High Tang" period) as being superior in quality to what came before and after, is subjective and evaluative, and often does not reflect the realities of literary history. Classical Chinese poetry forms The representative form of poetry composed during the Tang dynasty is the shi. This contrasts to poetry composed in the earlier Han dynasty and later Song and Yuan dynasties, which are characterized by fu, ci and qu forms, respectively. However, the fu continued to be composed during the Tang dynasty, which also saw the beginnings of the rise of the ci form. Within the shi form, there was a preference for pentasyllabic lines, which had been the dominant metre since the second century C.E., but heptasyllabic lines began to grow in popularity from the eighth century. The poems generally consisted of multiple rhyming couplets, with no definite limit on the number of lines but a definite preference for multiples of four lines.