Topic summary
Free-reed instrument

Extracted from the Wikipedia article Free reed aerophone.
Operation
In a free-reed instrument, it is generally the physical characteristics of the reed itself, such as mass, length, cross-sectional area, and stiffness, which determine the pitch of the musical note produced. Of secondary importance to the pitch are the physical dimensions of the chamber in which the reed is fitted, and of the air flow. As an exception, the pitch of the Chinese bawu and hulusi are determined by fingering recorder-like tone holes along the instrument body.