Parametrization of organ sound.

Abstract

This paper presents first results of a research project attempting a thorough analysis of pipe-organ sounds. Sound of individual pipes, as well as of combinations of pipes, of representative organs is being systematically acquired. The analysis is performed on a NeXT computer, and includes a variety of software tools such as spectrum analysis, time-domain waveform fitting, and sinusoidal analysis á la McAuley–Quatieri. In the analysis and presentation of the data, the considerable number of numerical results is reduced into a compact ‘‘fingerprint’’ of the whole organ, enabling an easy evaluation of the tuning system, quality of the tuning, and other parameters. Interesting results are obtained on a cross-talk between simultaneously sounding pipes: it is found that under appropriate conditions, two slightly mistuned pipes of different ranks but of the same nominal pitch will lock in a single frequency when sounded simultaneously; sometimes, this common frequency is higher than either of the two original frequencies (e.g., when two pipes sounding at 525.3 and 526.4 Hz lock at 527.7 Hz). [Work supported by the University of Washington Graduate School Research Fund.]