In the China of the Yuan, or Mongol era, various important developments in the arts occurred or continued in their development, including the areas of painting, mathematics, calligraphy, poetry, and theater, with many great artists and writers being famous today. Due to the coming together of painting, poetry, and calligraphy at this time many of the artists practicing these different pursuits were the same individuals, though perhaps more famed for one area of their achievements than others. Often in terms of the further development of landscape painting as well as the classical joining together of the arts of painting, poetry, and calligraphy, the Song dynasty and the Yuan dynasty are linked together. In the area of Chinese painting during the Yuan dynasty there were many famous painters. In the area of calligraphy many of the great calligraphers were from the Yuan dynasty era. In Yuan poetry, the main development was the qu, which was used among other poetic forms by most of the famous Yuan poets. Many of the poets were also involved in the major developments in the theater during this time, and the other way around, with people important in the theater becoming famous through the development of the sanqu type of qu. One of the key factors in the mix of the zaju variety show was the incorporation of poetry both classical and of the newer qu form. One of the important cultural developments during the Yuan era was the consolidation of poetry, painting, and calligraphy into a unified piece of the type that tends to come to mind when people think of classical Chinese art. Another important aspect of Yuan times is the increasing incorporation of the then current, vernacular Chinese into both the qu form of poetry and the zaju variety show. Another important consideration regarding Yuan dynasty arts and culture is that so much of it has survived in China, relatively to works from the Tang dynasty and Song dynasty, which have often been better preserved in places such as the Shōsōin, in Japan.