Abstract:

Tunes are played on the Great Highland bagpipe using the tone holes of its conical chanter. The much quieter practice chanter has holes with the same spacings on a narrow cylindrical bore. Differences between spherical waves in a cone and plane waves in a cylinder give rise to striking differences in pitch and tone quality. Drone pipes do not need to fit into either the conical family or the closed‐pipe family of reed woodwinds, because each drone produces only one note. A bass drone has three cylindrical segments, with diameters that increase in sequence, followed by an expansion chamber (bell and constricting cap) at the output end. Tuning slides between the cylinders create two additional expansion chambers with large diameters and adjustable lengths. (A tenor drone has two cylinders and one tuning slide.) Sound waves incident from either direction experience strong reflections at each jump in diameter, resulting in uneven standing waves and irregular input impedance curves that would be impractical for pipes with tone holes. Experimental results and computer models are used to relate the shape of a drone’s air column to its tuning and tone quality. [Work supported by the Paul S. Veneklasen Research Foundation.]