The Asian free-reed mouth organs

Abstract

Mouth-blown instruments employing a free reed coupled to a pipe resonator have long been known and used throughout East and Southeast Asia. Details of the origin and development of these instruments are not known, but are closely connected with the history and prehistory of a multitude of ethnic groups. These instruments exemplify a pipe–resonator coupling significantly different from the standard wind instruments of European origin. The free reed used is approximately symmetric, often operating on both directions of air flow. In some cases the reed is at or near one end of a closed pipe, but in other examples the reed is mounted in the side of a resonator open at both ends. The instruments can be either multiple pipe instruments with one pipe per note, or a pipe with a single reed and tone holes. A number of experimental studies have been conducted on examples of Asian free-reed instruments, primarily the khaen, bawu, and sheng. These include studies of reed vibration, measurements of sound spectra, and impedance measurements of the pipes. Comparisons have been made between experimental results and theoretical work on the coupling of reed vibration with the pipe resonator.