Music Listening, Music Therapy, Phenomenology and Neuroscience

8 – Micromodulation

147

The resulting sound is rich, complex and multilayered, strong and pene-

trating. This eruption of noise is related to a personal war memory of

Xenakis;

Athens - an anti-nazi manifestation - hundreds of thousands of

people droning out a slogan which is repeated in the shape of a

gigantic rhythm. Then, the fight against the enemy. The rhythm is

splintered in an enormous chaos of high penetrating sounds; whist-

ling of bullets; crackling of machine guns. The sounds begin to rarify.

Little by little, silence redescends on the city. (Xenakis/Matossian,

1981)

Micromodulation conveys emotional expression. In Coleman Hawkins'

recording of Body and Soul, described in chapter six, the modulation of the

saxophone tone communicates subtly shaded emotion.

Hawkins' melodic line is modulated by vibrato, portamento and

pitch bending integrated with refined variation and shading of timbre,

volume and fullness of tone. Not only the flow and form of melody, its

shape, expansion and contraction, but also the quality of every single

tone is crucial for Hawkins' musical expression.

The Musical Timespace

148

The continuous stimulation and maintenance of the listener's attention

and awareness is an essential function of micromodulation. In the begin-

ning of Ligeti's Atmospheres, the awareness of space-filling sound is main-

tained by vibrato and interference.

Micromodulation is essential for the naturalness of sound

Natural sound is never static. The timbral spectrum of natural sound is a

pattern of incessant variation and modulation. In the human voice, the

micromodulation by vibrato and tremolo reflects and communicates the

emotions and the physical state of the speaking or singing person.

In contrast to natural sound, a fixed spectrum of artificially synthesized

timbre which lacks variability does not maintain the awareness of the

listener. After a while, a fixed sound spectrum seems uninteresting. The

essential difference between fixed and variable spectra of timbre was

discovered by John M. Chowning in his experiments with synthesis of

timbral spectra by means of frequency modulation in the 1960's and 70's.

He states that

many natural sounds seem to have characteristic spectral evolutions

which, in addition to providing their "signature", are largely respon-

sible for what we judge to be their lively quality. In contrast, it is

largely the fixed proportion spectrum of most synthesized sounds

that so readily imparts to the listener the electronic cue and lifeless

quality. (Chowning, 1973)