The Piano Action as the Performer’s Interface: Timing Properties, Dynamic Behaviour and the Performer’s Possibilities

A concert pianist is able to produce a wide range of imaginable nuances of musical expression by actuating the 88 keys on a piano, none of which travel through a distance greater than one centimeter. In this study, we investigated the temporal behaviour of grand piano actions from different manufacturers using different types of touch (‘legato’ versus ‘staccato’). An experimental setup consisting of accelerometers and a calibrated microphone was used to capture key and hammer movements, as well as the acoustic signal. Five selected keys were played by pianists with the two types of touch. The analysis of the three-channel data was automated by computer software. Discrete measurements (e.g., finger–key, hammer–string, and key bottom contact times, hammer velocity) were extracted for each of the over 4000 recorded tones in order to study several temporal relations. Travel times of the hammer (from finger–key to hammer–string) as a function of hammer velocity varied clearly between the two types of touch, but only slightly between pianos. A travel time versus hammer velocity function found in earlier work [1] derived from a computer-controlled piano was replicated. Key bottom contact times exhibited larger variability between types of touch and pianos. However, no effect of touch type was found in the peak sound level (in dB as a function of hammer velocity).