Subjective Evaluation of Musical Scale Temperament in Pianos

Abstract

Piano tuners normally “stretch” the tuning, adjusting the upper strings of a piano sharp, and the lower strings flat, relative to the equally tempered scale. The desirability of this stretch (largely a natural consequence of tuning by beats) has apparently not been demonstrated formally, although there is anecdotal evidence that a piano tuned to strict equal temperament sounds less pleasant than one tuned with the typical stretch. The question assumes practical importance because of the relative simplicity of a device that would permit tuning to equal temperament by comparatively untrained personnel, in contrast to the much greater complexity of a similar device incorporating the stretch. Therefore, recorded tonal and chordal sequences from a small upright piano, tuned to an empirical average “stretched” scale by means of a visual device, were compared with similar sequences in which the same piano was tuned (1) to strict equal temperament (again using the visual device), and (2) by the conventional auditory method. The stretched scale was definitely preferred to strict equal temperament, both by Baldwin research engineers and by music students. No consistent preference for the auditory method of tuning was found.