Effect of generators and resonators on musical timbre in coupled systems

Abstract

The majority of Organ pipes are typical tone-generator/resonator systems, where the tone is either produced by an air jet or reed. My previous work on free reeds in pipe organs has raised my interest in how different sound generators affect timbre in terms of spectral balance and attack phase. Most recently, I have started to explore different tone generators with the soprano saxophone using custom adapters, including a brass mouthpiece from a cornetto, a bassoon reed and a free reed from the Chinese Bawu. Since the resonator remains the same, the role of the sound generator can be easily determined using a fast Fourier transformation and onset analysis of partial tones. With the brass mouthpiece, the soprano saxophone becomes an outward striking mechanism instead of a reed-based, inward striking mechanism. As a consequence, the instrument vibrates above the natural frequency of the conical resonator, and the B-flat instrument becomes a B instrument. It is important not to underestimate the range of the embouchure. In the case of the cornetto mouthpiece, it took some practice to attain the higher harmonics. Naturally, the spectrum with the cornetto mouthpiece is very similar to that of a regular soprano saxophone. [Work supported by NSF #1002851.]