Abstract:
The frequency and amplitude of vibration of a representative sample of reeds from American reed organs have been studied as functions of the (negative) static pressure difference between the interior and exterior of thewindchest, along with the spectrum of the near-field sound. Over a pressure range that includes the normal playing pressure of the instrument, the frequency initially tends to decrease in an approximately linear fashion with increasing blowing pressure, but some anomalous effects are observed at higher pressures, including an increase in frequency at very high blowing pressures. Some hysteresis effects are also observed in the frequency--pressure relationships. The effects of constrictions to the airflow, simulating the effect of a partially opened pallet, have also been studied.