7 – Density, Extension and Color of the Soundspace133In 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 inchapter 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 strongemotional response in the listener, experienced as a climax when the total
range of the soundspace is expanded towards the limits of pitch perception.