The earth has a complex and delicate balance of ecosystems that sustain a diversity of life forms. Human intervention is now altering this balance in unprecedented ways, most notably from rain forest eradication, and the various effects of global warming.  The geographer Robert Bailey has classified terrestrial ecosystems into four domains (polar, humid temperate, dry, and humid tropical) divided into 15 regions. All of the earth's land mass fall into these 15 classifications in various percentages, from savanna (17%) to hot continental (1.4%). This is a dynamic equation that human intervention is altering quickly and dangerously.

This piece draws on Bailey's classifications as a formal model. There are sixteen sections (in one continuous movement) that take their temporal proportions from the percentages of their corresponding ecosystem, presented in the following order (with cities given as one example of where each ecosystem may be found):

1. atmosphere                       9. tropical steppe (Khartoum)

2. subarctic (Fairbanks)           10. tropical desert (Djibouti)

3. tundra (Reykjavik)              11. rain forest (Manaus)

4. warm continental (Tallinn)      12. savanna (Madras)

5. temperate steppe (Volgagrad)    13. temperate desert (Taschkent)

6. marine (Paris)                  14. subtropical (Sydney)

7. hot continental (Nagano)        15. prairie (Montevideo)

8. mediterranean (San Diego)       16. icecap (Byrd Station)

Some data about each regions climate is taken into consideration in developing the material for each section, particularly the way temperature and precipitation change over the course of an average year. But other then this, the music is composed freely, with no attempt to illustrate. I do not seek to create a musical picture of these systems, but rather use this data as a model for a journey through a varied musical terrain. I also wish to celebrate the present diversity of ecosystems, and lament the gradual erosion of this diversity and corresponding extinction of numerous life forms.

Ecosphere is scored for flute (with piccolo and alto), oboe (with cor anglais), 2 clarinets (with bass, and contrabass), two horns, trombone, 2 percussionists, 2 keyboards, and string quintet. The keyboards control sample players to simulate various plucked and struck instruments, with a computer deployed to dynamically retune the samples in a just relationship to the fundamental frequency of each phrase. Real-time audio signal processing is deployed on all of the other instruments for spatialization, resonance, reverberation, delay, cross synthesis, and just intonation pitch shifting.

Ecosphere was commissioned by IRCAM. I wish to express my gratitude to Eric DeVischer and Allain Jaquinot for their support, to Miller Puckette of UCSD for his software development, and to Olivier Pasquet of IRCAM for his indispensable assistance with the technical realization of this work. 

On the morning of 11 September 2001 a terrible act of cruelty occurred in my place of birth, New York City. Perhaps a work of art seems trivial in light of the disastrous consequences of this act. But however insignificant it may seem, I must offer this piece in dedication to the memory of the victims of this tragedy.

Stage Diagram:

Microtonality:

The following special accidentals are used to indicate specific micro-intervals for just tuning. In the case of the horns and trombone, these pitches are to be realized by playing natural notes.

Flute:  square note heads indicate a "tongue ram" played at pitch, and sounding one octave lower

Oboe Multiphonics:  The following multiphoncs (with fingering suggestions from the Nora Post article) are specified in the score:

Horns:  All glissandos are to be played as harmonic glissandos, and all trills are to be played as lip trills (except where indicated otherwise). When a trill pitch is not indicated in parenthesis next to the main note, the trill should be played to the next highest partial. All microtonal pitches specified are to be played as "natural tones" in the corresponding series. For example, F with a 49 cent quarter flat indicates playing the 11th harmonic in the series of B, while F with a 31 cent flat indicates the 7th harmonic in the series of G.

Trombone: Glissandos are to be played with the slide, unless the indication "Harm." appears above the gliss., indicating a harmonic glissando. All trills are to be played as lip trills to the pitch indicated, or to the next highest partial. As in the horn parts, microtonal notes are to be played as natural tones wherever possible, including high partials on the bass side of the instrument. A few notes in the part are not possible to play this way, and in that case the pitch should be adjusted by using the slide. But this should only be done when it is the only alternative. When using the harmon mute, the stem is to be fully inserted. When a + is indicated above the part, the end of the stem should be covered with the left hand, and an O indicates leaving it completely open. A line between an + and O indicates a gradual change from one to the other to create a timbral transformation.

Keyboards: The two keyboard parts are played on 88 key midi keyboards that controls a 32 channel, 128 voice E4X Sampler, through a mediating computer program. The lowest octave of the keyboard does not trigger audible notes, but rather indicates to a computer program a fundamental frequency to which other notes of the keyboard are then adjusted in a just relationship. Therefore the notes produced will not all be tempered, as they appear in the score. A hybrid just tuning scheme is deployed, where the intervals of the major third (5th harmonic, -14 cents), tritone (11th harmonic -49 cents), minor sixth (13th harmonic, +41 cents), and minor seventh (7th harmonic, -31 cents). For example, if the lowest note (A) is depressed, until another note in the lowest octave is depressed, all C#'s will be lowered 14 cents, all g's will be lowered 31 cents, etc. When a diamond shape note head (like those used to indicate string harmonics) appears in the left hand of the keyboard part, it is to be played ONE OCTAVE LOWER THAN NOTATED, and it indicates the playing of one of the silent fundamental notes explained above.

Percussion:  Both percussionists play vibraphones, and identical sets of non-pitched instruments, notated as follows:

In addition, percussion one has a chromatic set of 13 tuned aluminum pipes, from D3 to D4, tuned 31 cents flat, and crotales (lower octave). Percussion two has a chromatic set of 13 tuned aluminum pipes from A#3 to A#4, tuned 49 cents flat. (If pipes are not available, a mallet Kat controller will be used instead to trigger recorded pipe samples.) The notes for the pipes are indicated as tempered notes in the score.