recording, microphone placements and sound analysis, are described in detail in chapter three, ‘Vibrations and Tone’. The sounds of both these specific pianos were used to produce all the comparative data in this chapter and for the following chapters on jazz trio tone comparison and audience surveys. Compositions based on Aboriginal music collaborations were created using the particular sounds of the M19(STU) Stuart piano, as described in Chapter 6.
The intricate analysis of sound quality in this chapter is introduced by a summary of eight sounds of the M19(STU) and STE pianos, presented in brief one page analyses, displaying the qualities found to distinguish the Stuart sound from the Steinway sound. To keep the overall analysis to one page, the text is in a condensed font. It is necessary to read the decay graphs in colour. If colour isn’t provided in this text,the graphs can be viewed in the PDF files of this text, provided on the accompanying USB drive.
Following the summary of eight sounds, the tonal distinctions of the Stuart and Steinway piano sounds are analysed in detail by five aspects of piano sound quality: i) Rate of Decay; ii) Time of Transition to the Steady Modes of Oscillation; iii) Range of Harmonic Spectrum; iv) Directivity of the Sound; v) Projection of the Sound.
Because the loudness and amplitude of the Fundamental, 2nd and 3rd partial frequencies of a sound are indicators of tonal colour, this study identifies the transient presence, balance and activity of the partial simple tones within the composite complex tone sound of a piano note, its harmonics.
The relative proportion with which each overtone intervenes in the resulting vibration determines to a great extent the particular character, quality, or timbre of the generated tone. 237
The coupling apparatus on the Stuart piano bridge, the bridge agraffe, was shown to change the vibrational modes of the string, in chapter 2. The vibration modes in the string oscillation are harmonic, and therefore these modes influence tone colour.
Directivity and Timbre.
The contrasts in perspectives and perceptions of what an audience ‘hears’, and what the pianist ‘hears’ are assessed by examining the radiations of piano sound to different positions and distances within the performance space. The tones are ‘captured’ by the microphone array of 180°, at distances of 3 metres and 6 metres, from the pianos
Sound is not radiated uniformly in all directions by an instrument; the pattern of directionality is likely to be different for different harmonics 238
237 8 Roederer, 118.
238 8 Meyer,Acoustics and the Performance of Music. (1978).source : 6 Campbell& Greated,145.
