7 – Density, Extension and Color of the Soundspace
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In the recording, a section between two broken lines corresponds to a
duration of a little more than one second. The tones within a section are
perceived simultaneously as a fluctuating harmonic color.
Ligeti's harpsichord piece is a continuum of interactions and transitions
between listening dimensions. The sharply attacked tones of the harpsi-
chord possess the double quality of bright metallic timbre and distinct
pitch, and the continuous stream of rising and falling tones evokes the
simultaneous experience of pulse and movement. In the pulsating streams
of timbre and pitch, rhythmic structures, melodic lines and harmonic
colors emerge and disappear. The secondary listening dimensions rhythm,
melody and harmony arise from the interactions of the basic dimensions
timbre, movement, pulse and pitch height.
This music is an exploration of the temporal continuum described in
chapter one. The temporal continuum is divided into four sub-
areas by the processes of auditory perception, the microtemporal areas of
timbre and pitch height and the macrotemporal areas of pulse and move-
ment. Ligeti explores these temporal sub-areas by approaching the limits
of transition between one area and another. The pulse of the rapid attacks
is so fast that it approaches the limit of approximately 16 beats per second,
where the transition from perceptible pulse to perceptible pitch takes
place. The expansion of the soundspace downwards is so large that the
lowest pitches approach the same limit. Simultaneously, the soundspace is
expanded upwards, so that the highest pitches approach the upper limit of
perceptible pitch.
The accumulated totality of these processes may call forth a strong
emotional response in the listener, experienced as a climax when the total
range of the soundspace is expanded towards the limits of pitch perception.
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8
The final model of nine listening dimensions
Micromodulation is the ninth listening dimension
In the previous chapters, eight listening dimensions have been discussed,
the five basic dimensions intensity, movement, timbre, pitch height and
pulse, and the three secondary dimensions rhythm, melody and harmony
which arise from the interactions of basic dimensions. The relationships
between these dimensions are shown in the model Fig. 6.5.
The remaining open field in the model represents micromodulation.
Micromodulation arises from the interaction between timbre and pulsa-
tion. Examples of micromodulation are vibrato, tremolo and flutter-
tongue.
Vibrato is a micromodulation arising from a pulsating varia-
tion of intensity and pitch focusing in the timbral spectrum. The pulse
pattern interacting with timbre may be fast or slow, regular or irregular,
resulting in different shadings of vibrato.
Tremolo is a micromodulation of timbre arising from pulsating varia-
tion of intensity and attack quality. The flutter-tongue playing of wind
instruments is a specific kind of tremolo, produced by the transformation
of a continuous stream of timbre into a rapid succession of attacks.
Interference is a particular kind of micromodulation, arising when two
pitch-focused timbral spectra interact with each other, producing pulsating
interference beats or a focusing at an emergent pitch.
Musical effects related to vibrato, tremolo and interference are trills,
glissando and pitch bending. Complex and irregular forms of micromodu-
lation are fluctuation, shimmering and distortion and the noise-like
timbral qualities produced by special ways of playing such as the col legno
and sul ponticello effects of stringed instruments.