Sheng

Tang Dynasty
Beilin Museum, Xi'an

The sheng is a reed instrument, consisting of bound pipes serviced by a single wind box, that can play chords as well as melodies. Each pipe sounds one note, which is activated when a hole in the side of the pipe is stopped with the fingers. This works because a reed is inserted into each pipe, in such a way that the reed only vibrates when the side-hole is closed (when the side-hole is open, air just rushes out the side-hole instead of resonating through the pipe). A drone effect is also possible, simply by plugging the side-hole in one or more of the pipes.