Beijing Opera is one of China's national treasures, which combines acting, talking, singing, music, dancing and acrobatics together. It (begin)in the late 18th century. There are four roles Beijing Opera performers can play: sheng, dan, jing, chou. Each role has its own singing and acting styles. Performers often sing with very high voices. This is Beijing Opera was usually performed open-air stages in the early days. In order to be heard over the crowds, the music had to be loud and performers had to sing in very high voices.
