In my piece Winter Trees, vowels extracted from a poem by Sylvia Plath orchestrate the music, giving each fundamental pitch a specific array of resonating spectral elements. The acoustic properties of the voices (two sopranos and alto) are combined with the acoustic properties of the three instruments – alto saxophone, bassoon, and cello to create the compositional structure. The poem is used in such a way that the ear moves freely between sound and meaning, focusing at times on a single line, following a thread of meaning as it slips from voice to voice, and at other times allowing the assonances and dissonances to wash through it as the voices become submerged into the texture. The text provides a lexicon of language sounds, as well as a thread of meaning.

The first section contains words and phrases from the first part of the text. The succession of words in based on the spectral content of vowels. The meaning is ambiguous, as some words emerge from the texture. The piece begins with the vowel [a], a single voice concentrated on a point of resonance in mid-register. With this range as a starting point, there is a gradual widening of the spectrum above and below [a] as the second and third voices move within a close frequency range of the central pitch. The movement of sounds is a gradual transformation in timbre and texture from spectrally simple to spectrally complex. This is followed by a section of contrasting vocal sounds — ululations and jaw trills. Ululations are perceived by the listener as a rapid, relatively even repetition of a basic vowel sound – similar to the sound children make when imitating sheep. This sound is produced with a combination of creaky voice (partial constriction of the larynx, resulting in a low-pitched, creaky sound) and glottal stop (total constriction of the larynx). This articulation results in a movement from a wide spectrum to a narrow spectrum. Ululations are common in Bulgarian vocal music and also appear in the music of Monteverdi as goat trills. The spectrum widens again with jaw trills – wide vibratos created with a relaxed jaw on the phonemes [wi- yi-yi]. The movement to this sound creates a shift in spectral energy to the high end of the spectrum, and the movement of voices and instruments creates a layering of spectral density, leading to a concentration of spectral energy in the high frequency range [i]; gradually descending to [a]. (Fig.1)

Fig. 1: Ululations