Sound production in Asian and Western free‐reed instruments

Abstract

There are two families of free‐reed instruments. This paper summarizes some of the research on both done in recent years, with emphasis on differences in history and means of sound production. The Asian mouth‐blown instruments are of ancient origin and use a free reed coupled to a pipe resonator. The sheng, sho, khaen, and bawu are typical examples. These reeds are approximately symmetric, typically cut from a single strip of material, and often operate on both directions of air flow. They behave as blown‐open or outward‐striking reeds, with playing frequency above both the resonant frequency of the pipe and the natural frequency of the reed. The Western free‐reed family originated in Europe about 200 years ago and includes the reed organ, harmonium, harmonica, and the accordion‐concertina family. In these the reed tongue is offset from the opening in the frame. This permits operation on only one direction of air flow, and pipe resonators are not required and generally not used. The playing frequency of the air‐driven reeds is normally below the natural reed frequency and, if the reed is coupled with a pipe, below the resonant frequency of the pipe as well.