Partial tones and tuning of American-made bells

Abstract

A study over the past 20 years has involved recording the relationship of the first five important partials in the sound of a large number of American-made bells by several founders, together with major physical dimensions of the same bells. This has allowed the correlation of the partial configurations with what might be termed ‘‘family profile’’ characteristics of these several major founders. It has been found that in such bells the deviation of the prime from the theoretically ideal octave relationship with the nominal is generally in the range +1/2 to +2 semitones; while, at the same time, the deviation of the hum from the theoretically ideal 2-oct relationship with the nominal has been found generally to be −1 to −3 semitones. Such deviations had formerly been considered uncorrectable by standard tuning methods (machining). However, from these data, and from practical experiments, it has proved possible to develop a general approach to tuning such bells, allowing principally the correction of the important octave partials (hum, prime, and nominal). This approach has made practical the tuning of several peals and chimes, one of which has been added to, with similarly scaled bells, to form a musically successful carillon.