Solar Organetti
Please reference this paper for a full description of the project. There is also this video, and a lower resolution video. Introduction In this project, the desire was to create modular, organic sound objects powered by the sun. The objects would breathe with the brightness of the sun, and have a subtle and complex envelope: some sort of ground to some beautifully tuned wind chimes heard in a garden. They would from trees and light posts, like fruit or icicles. The interactive portion of the organetti is compositional: they set in motion by design choices, yet subject to chance (weather). Background There were some interesting historical precedents for such a project. Along with the Utrecht Psalter, the Stuttgart Psalter from c. 820-830 illustrates various organs and other instruments. Likely made in a northern French scriptorium, the manuscript illustrates Psalm 136/137 ("By the rivers of Babylon...") with little organs hanging from trees; this image is found in early Greek Psalters as well. These organetti, possibly a fantasy, a miniature of reality, and/or an artistic convention, differ from the solar ones in that they have seven pipes each, six or seven little key-tabs below the pipes, a frame, and an oblique bar across the pipe rows. Later representations become less reliable until perhaps the later thirteenth century [4]. There may be some connection with the panpipes sometimes shown hanging in foliage in pagan Roman sculpture (see figure 1). Another account of interest hails from the Lakota Sioux. The Lakotan Siouan Sundancers blow a bird bone whistle that serves as a conduit between the source of power and humanity, that is, Wakan-Tanka and the Sundancers. During the Sundance, power is said to flow from Wakan-Tanka through the sun and the sacred central tree in the dance ground, to the Sundancer, who blows a hollow bird bone whistle, which fills with that power [1].
The term organetto in Italian refers to a bird, as well as a type of pasta; in this case, we refer to a small portative organ, with one hand playing the pitches, and the other pumping the bellows (figure 3). The solar organetto has some of the same characteristics as the traditional one: it’s portable, uses pipes, and has its own source of wind power. It would be up to the artist to decide the number of solar organetti and their position. There are also organetti morti, which are non-functional pipes introduced into the façade of a pipe organ to achieve visual symmetry. For information on the solar engine, the details are provided in this paper. Implementation
The path of the sun in the sky is determined by where on Earth the organetto is. Lower latitudes get more sun, and therefore more current, however higher latitudes have longer days some parts of the year. There are excellent models for computing the sun’s position and solar intensity at various stations around the world [14]. Neglecting weather, global dimming, and other chance factors, these data could be used to get more precise performances from the system; the performance would change daily, albeit subtly, producing complex variation over timescales that are longer than a typical composition (months rather than minutes). There are weather patterns that occur over long enough periods that one could surmise that, for example, it will run less often in Seattle than in Florida. Depending on the panels’ location, the sprouting of leaves on trees, shadows from new buildings, and other exogenous occurrences would change the system’s behavior. In this organetto, at this time of year (30 January 2007), and at this latitude (New York City is 40æ43’ N), from sunrise the system charged until there was a first cycle, which was 8 seconds on and then a span of minutes off. Sunrise was at 7:07AM (112æ E-SE), noon was 12:09 PM (sun at 32æ above horizon), and sunset was at 5:12PM (248æ W-SW). The off period shortened as the sun rose in the sky. When the sun neared its zenith, the off interval was only 15 seconds. The off periods grew longer at sunset’s approach, until there was no more sun and the system waited for the next sunrise.
Conclusions There are many other types of wind-blown sound elements that could be used, for example, ocarinas, made of clay, conch shells, and glass (embedded with a solar-collecting layer). One could also use the engine to create percussive instruments and plucked-string instruments. With more sound sources, there are more possibilities.
See paper
for references and footnotes.
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Figure 1. Sacrifice to Hercules. Note pan pipes in arbor. [2] |
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Figure 2. Pan. Note foliage from syrinx. [5] | |
Figure 3. Musician with portative. [6] | |
Figure 6. Morning Sun, Brooklyn | |
Figure 7. Collecting energy through window, afternoon. | |