>> Golan Levin, Zachary Lieberman, "Messa di Voce", 2003

"A performance and installation in which the speech, shouts and songs produced by two vocalists are augmented in real-time by custom interactive visualization software." (Golan Levin, Zachary Lieberman)


from the project's website:

"overview:
Messa di Voce (Ital., "placing the voice") is an audiovisual performance in which the speech, shouts and songs produced by two abstract vocalists are radically augmented in real-time by custom interactive visualization software. The performance touches on themes of abstract communication, synaesthetic relationships, cartoon language, and writing and scoring systems, within the context of a sophisticated, playful, and virtuosic audiovisual narrative.

Tmema's software transforms every vocal nuance into correspondingly complex, subtly differentiated and highly expressive graphics. These visuals not only depict the singers' voices, but also serve as controls for their acoustic playback. While the voice-generated graphics thus become an instrument which the singers can perform, body-based manipulations of these graphics additionally replay the sounds of the singers' voices — thus creating a cycle of interaction that fully integrates the performers into an ambience consisting of sound, virtual objects and real-time processing.

Messa di Voce lies at an intersection of human and technological performance extremes, melding the unpredictable spontaneity and extended vocal techniques of two master composer-improvisers with the latest in computer vision and speech analysis technologies. Utterly wordless, yet profoundly verbal, Messa di Voce is designed to provoke questions about the meaning and effects of speech sounds, speech acts, and the immersive environment of language.


background:
Messa di Voce, like our previous augmented-reality artworks RE:MARK and Hidden Worlds of Noise and Voice, is concerned with the poetic implications of making the human voice visible. In Messa di Voce, the core technology which makes this possible is a custom software system which integrates real-time computer vision and speech analysis algorithms. Specifically, a computer uses a video camera in order to track the locations of the performers' heads. This computer also analyses the audio signals coming from the performers' microphones. In response, the computer displays various kinds of visualizations on a projection screen behind the performers; these visualizations are synthesized in ways which are tightly coupled to the sounds spoken and sung by the performers. Owing to the head-tracking system, moreover, these visualizations can be projected such that they appear to emerge directly from the performers' mouths. In some of the visualizations, projected graphical elements not only represent vocal sounds visually, but also serve as a playable interactive interface by which the sounds they depict can be re-triggered and manipulated by the performers.

Our group's interest in phonesthesia, or phonetic symbolism, is at the heart of the Messa di Voce project. According to this idea, the sounds of words tend to reflect, to some extent, associated connotations from other perceptual domains such as shape or texture. A classic illustration of the phonesthetic principle can be found in Wolfgang Köhler's pioneering psychology experiment from 1927, in which he asked subjects, "which of the figures below represents the sound maluma, and which one represents the sound takete?" Nearly all viewers respond with the same answer — suggesting rich research opportunities for artmaking and cognitive psychology alike.
Messa di Voce brings together findings from phonesthesia research with our group's shared interests in abstract language, extended vocal techniques, interactive systems, and live audiovisual performance. In our concert, these ideas take shape in a series of twelve brief vignettes which explore different symbolic, tactile and audiovisual aspects of phonesthetic relationships. The entire Messa di Voce performance generally runs 30 to 40 minutes in length."