Sheng is a mouth-blown free reed instrument consisting essentially of vertical bamboo pipes. The age of sheng is unknown, but there were ancient pictographs of the instrument dating from 1200 B.C. Traditionally, sheng has been using as an accompaniment instrument in kunqu and some other forms of Chinese opera, as well as in a number of regional instrumental genres. It is until the 1950s that sheng was valued as an outstanding folk musical instrument in China and was then developed to become a solo instrument. Sheng comes in different sizes. The present-day models consist of 21, 24 or 36 reeds (or pipes), and there are extended models especially designed for orchestral use such as the amplified sheng, the alto baosheng, paisheng, etc.