Pianist playing piano. Credit: thuynhienbananachan
A new study has found expert pianists effect the timbre of their performance by varying the timing, synchronicity, velocity and acceleration of their keypresses.
“It has been debated over a century whether skilled pianists can alter the timbre – or tonal quality – of notes through nuanced motor actions, although it is a common belief among pianists,” write the authors of the study published in PNAS.
The researchers recorded 20 expert pianists as they played a melody with the same tempo and loudness. The players were asked to alter the perceived timbre of their performance by playing the music with 6 different expressions: light vs heavy, clear vs blurred and bright vs dark.
“We developed an innovative high-resolution sensing system capable of capturing piano key movements with exceptional temporal (1ms) and spatial (0.01mm) precision without mechanical interference to the keys,” the authors write.
“This technology enables a comprehensive analysis of the subtle motor actions employed by expert pianists and their impact on perceived timbre, allowing us to explore previously uncharted aspects of sensorimotor performance.”
HackKey, a high-resolution sensing system of piano key movements. Credit: Shinichi Furuya
Audio recordings were then presented to 20 other pianists, and 20 nonmusicians, to see whether they could correctly identify the intended timbres of the performances.
“Our listening experiment showed that listeners reliably perceived timbral variations as intended by the pianists, although pianists exhibited better auditory discrimination of the target tone timbres (i.e., weight, clarity, and brightness) than nonmusicians,” they write.
The researchers identified 5 specific key movements which were linked to these variations in timbre.
This included the time taken between keypresses, synchronicity of movements between the hands, the piano keys’ descending velocity and the ‘acceleration at escapement’, which the authors describe as “the moment when the hammer momentarily detaches from the key mechanism just before striking the string”.
“These results suggest that piano timbre perception is shaped not solely by the physical properties of a single keystroke but also by the relationships of both a sequence of piano tones and simultaneously produced piano tones,” they write.
“Our findings underscore the pivotal roles of subtle physical gestures in creating the rich timbral palette of piano tones, advancing our understanding of the intersection between motor control and artistic expression.”