On the acoustics and psychology of piano touch and tone

Abstract

By way of ‘‘the touch,’’ a pianist is able to achieve two degrees of freedom in the control of the key motion. Besides the final hammer velocity, the pianist can control, to some extent independently, the force history between the key and finger. By controlling the acceleration history of the key, while keeping the final hammer velocity constant, the pianist can vary the duration of the key and hammer motion and the forces between the interacting parts of the action. This will influence the intensity of vibrations in the hammer shank and of a noise precursor in the radiated sound. This report addresses the pianist’s ability to change the touch parameters and to control them (at will) for musical purposes. The traditional controversy between physicists and some pianists raises a psychological question: ‘‘Why do some pianists think they are able to control a timbre of the individual tone by touch?’’ One hypothesis is that variations in touch change the perception of a tone for the pianist, but not for a listener, because for the pianist the tone perceived starts at finger–key contact, while for a listener it starts when the hammer hits the string.