The xiao is a longitudinal flute, has been said to originate from Xi Qiang (present day Gansu) during the Han Dynasty (2002 BC to 220 AD). It was called a qiangdi then and had four playing holes. By AD 247, the qiangdi had appeared with six playing holes. This instrument is similar to the present day of xiao.
Xiao, otherwise known as dongxiao, is made of wood and is blown vertically. It has eight keys and is commonly used in the orchestra. Xiao was often played with the qin in the past.
Xiao is a soft-pitched instrument with a limited range of dynamics. Its tone is sweet and tranquil. Music of xiao is characteristically gentle, silent and peaceful.