Mistuning Desirable in Organs, Pianos, Choruses, and Orchestras

Abstract

See paper D1, American Physical Society meeting, June 26, 1951. Tone quality of a chord depends on more than the strength of harmonics. Organ builders have for years included “celeste” stops amongst the softer stops. They consist of two or more ranks of pipes, mistuned about 0.1 semitone (approximate pitch threshold of ear) to produce beats which increase in frequency with pitch; when a chord is played there is a scintillation of tone which is more subtle than the tremulo in which all tones vary in volume synchronously. A pipe organ played at full volume needs no intentional mistuning as there are then many pipes speaking one pitch and it is impossible to have all pipes for a given pitch, tuned perfectly to each other. Electric organ companies have failed to realize the importance of “celeste” or “chorus” stops—two use them but only in a limited way. The same effect is observed if the three strings of a piano note are not too well-tuned. A chorus sounds better than a quartet and a full string orchestra sounds better than a string quartet for the same reason—no two violinists (or singers) can possibly play (or sing) exactly the same pitch.