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er known for his exploration of adjust to morph from an [i] to an ing the visual flow of the score. My
vocal timbres for vocal ensembles. [u] vowel, while harmonics are own composition, Hymn to Aethon, is
In this example, Twining asks the made audible by an overall narrow- an example of a piece that layers
vocalist to start with an [i] vowel, ing of the vocal tract. these various timbres to create cer-
20

which is made brighter by shifting These symbols have also been tain musical effects (Figure 6).
to an Overtone Dominant sound, adapted into noteheads to delineate Using these noteheads to indi-
and moves through to an [u], thus among desired timbres without af- cate which sound to use allows the
changing to sound to a less bright, fecting the traditional notation of precise notation of four diff erent
but still Overtone Dominant, tim- pitch and rhythm. A variety of tim- timbres within a few bars, presented
bre (Figure 5). bres can then be easily combined in without the distraction of many de-
In this case, the tongue and lips a single passage without interrupt- scriptive words for each desired tim-
bre. In this segment, the lower voic-
es sing an ostinato with a focused
and bright timbre, while the upper
voices sing a melody using the Fun-
damental Dominant sound, thus
creating a timbral contrast between
the rhythmic accompaniment and
the lyrical line. All voices crescen-
do into a sudden Wide Spectrum
sound and resolve with the altos
singing a subtle “fi lter sweep,” cre-
ated through the use of changing
harmonics, that transitions into the
next section.

Limitations of Using the
Spectral Envelope to
Identify Vocal Timbre
While looking at spectral enve-
lopes can provide a level of visual
understanding of these timbres,
there are certain limitations to what
a spectrograph can capture and
how that image relates to the aural
experience of timbre. A spectral en-
velope of a sustained tone doesn’t
take into account articulation, the
attack-decay envelope, or other en-
vironmental factors that eff ect the
perception of timbre. In addition,
vowels emphasize particular fre-
quency bands that are consistent
across ranges and pitch spectra,