A Study of the Tuning of Pianos

Measurements of the pitch of each note on the piano were made immediately after tuning by means of the chromatic stroboscope. Sixteen grand pianos and twelve upright pianos were included in this study. Different makes of pianos were used and the tuning was done by different tuners. Averages were computed for each of four tuners, using three grand pianos by each tuner, to discover whether or not different tuners follow different patterns of tuning. The conclusion is that they follow, on the average, about the same pattern with individual differences on the extreme ends. With this established the average was then taken of sixteen grand pianos to determine the slope of average deviation from the equally tempered scale. A line drawn to true fifths much more nearly coincides with the line of averages than does the line of true octaves and is very close for the middle five octaves. At the ends the departure is considerably greater. For the twelve upright pianos the departure is still greater. A variety of causes seem to contribute to the “stretching” of octaves. In harmonic overtones in the bass and over compensating to avoid “flatting” are probably most significant.