Vol. 30 Issue 2 Reviews
Agostino Di Scipio: hörbare ökosysteme, live-elektronische kompositionen 1993-2005

Compact disc, 2005, Capstone Ed RZ 10015; available from Edition RZ, c/o Durand, Klausenerplatz 11, D-14059 Berlin, Germany; World Wide Web www.edition-rz.de/.

Reviewed by Steve Wanna
San Francisco, California, USA

CDIn his 2003 paper, "Sound is the interface: From interactive to ecosystemic signal processing" (Organised Sound 8/3: 269-277), Agostino Di Scipio describes what he considers to be truly interactive music as music in which interaction is essentially reciprocal communication between all members of an interactive system. An interactive system may include: 1) some sound source(s), a digital sound processing unit (DSP), an “agent” (person controlling the DSP), any performers, and 2) a space (and all its components) to host and interact with these elements. All these components are typically treated as equals. In this music, sound is the result of interaction rather than a reason (or a map) for it. Interactions between components of the system can be, and, indeed often are, purely sonic, or mediated through sound.

Mr. Di Scipio distinguishes this kind of music from music in which the interactions are often nothing more than non-reciprocating reactions (sound processing that is not dynamic or adaptive). Furthermore, he proposes that “the DSP algorithms, and the methods by which they communicate among themselves, should be seen as the material implementation of a compositional process or concept” (ibid). This, in his view, reflects “a paradigm shift from interactive composing to composing interactions” (emphasis in original). These composed interactions, in turn, yield sonic results which we may (or may not) perceive as music. As Mr. Di Scipio puts it, “the shift is especially relevant when composed interactions are audibly experienced as a music of sound (timbre composition), more than a music of notes (as is often the case with interactive music systems, especially when instrumentalists are involved).” It is this notion of composing or defining the interactions rather than the actual sonic results that is at the heart of much of this composer’s recent work and is the basic principal underlying all the works featured in the present recording.

This CD, dedicated entirely to the music of Mr. Di Scipio, includes four works that collectively trace the evolution of the composer’s interest in, and treatment of, the subject of live-electronics and room-adaptive or room-dependent music over the past decade. All four works utilize live electronics and two involve instrumentalists (again, as components of an interactive system). The use of live electronics is consistent in the four works and relies on “room-dependent” DSP that is actively “listening” through microphones scattered throughout the space to the total sound output in order to adapt its own behavior accordingly. In all four works, the composer defines a set of possibilities or paths of interactions that the components of the system (including instrumentalists, when present) can follow. These possibilities are, themselves, dynamic and do change as a factor of the feedback from the sonic result or output. In a sense, they become part of the interactive system rather than mere paths to be followed rigidly.

As the title of Mr. Di Scipio’s aforementioned article suggests, the various components of the system communicate exclusively through sound. Any change or adjustment of behavior on the part of any component within the system is governed only by a set of prescribed limitations and the sonic feedback it receives within the system. Again, it should be restated that the system may include any or all of a number of components (the DSP, instrumentalists, the performance space, even the audience as part of the space). Even in the pieces that involve instrumentalists, the “score” from which they read amounts to nothing more than instructions about actions that lead to sounds, rather than pre-conceived and pre-shaped sonic ideas or graphic representations of sounds to be realized by the performers.

Integral to all these pieces is a sense of openness where each performance (realization of some interactions) and its emergent sonic result (the music) are subject to the specific conditions (properties of the space, etc.) present at the time. All variables involved guarantee that the form of each piece, not having been pre-composed, will, rather, emerge in the process of performance and be perceived as the resultant timbre (or total sonic output).

Another very important underlying principal common to all these works and to the general approach to the compositional process itself is the strong interdependency or reciprocity between empirical and theoretical approaches. While this is quite common in electroacoustic music in general, both in the composition process (experimenting with sounds, etc.) and the performance process (adjustments are always needed when dealing with different spaces and equipment), it is of particular relevance here. In all these works, the sonic output is never predetermined, but rather emerges as the result of the interaction between the components of the system in a space. The adjustments that are typically needed to optimize a performance in a particular space, in this case become vital and necessary for the very existence (emergence) of the work. In this set of compositions, the feedback on which composers typically rely to propel their learning experience is an essential element of the music itself. Both composer and performer must rely on a thorough understanding of both the theoretical principals as well as the live process to facilitate the emergence of any sonic output (music).

For obvious aesthetic reasons, the arrangement of the works as tracks on the CD is not chronological. Instead, purely electronic works alternate with ones that incorporate instrumentalists. For clarity, however, the pieces will be examined here in their original chronological order.

The first work, Texture/Multiple (1993), was initially a reworking of an earlier piece for soprano sax and electronics titled Kairòs (1992). It was subsequently expanded, over the course of several performances, into a piece with a variable number of instruments and a duration between 12 and 14 minutes. The present recording, lasting just over 12 minutes, features the most expanded version for violin, cello, bass flute, bass clarinet, piano, vibraphone and, of course, live computer processing. As with the other pieces on this disc, Texture/Multiple is an interactive piece: each member of the ensemble is, at once, independent, part of the instrumental group, and a component of the entire interactive system. The sonic material is a mixture of sustained sounds and rapid attacks, which are subjected to live processing (time-stretching, granulation, etc.). The design of the piece is such that it allows performers to create a variety of textures that coalesce or break apart depending on the performers’ individual inclinations and their shared reactions to the electronics. As mentioned earlier, the live processing is dynamic and room-dependent, meaning it reacts and adapts to changes in the acoustic response of the space.

The third piece on the CD shares with the first the presence of instrumentalists. 5 difference sensitive cyclic interactions (1997-98) is a piece for string quartet and interactive computer processing. The instrumental parts consist of patterns of micro-rhythms, articulated by a relatively restricted range of sonic material including pizzicato, bow scrapes, and other noisy sounds. These, along with the live processing (mainly real-time sound granulation), interweave in a rough, grainy polyphonic mesh of noises and interferences. Here, as in the other works on this recording, Mr. Di Scipio relies on microphones scattered in the space to allow the computer to “hear” the space and all the sounds that enter into it, making the space an inseparable component of the system. The computer matches the sounds coming directly from the instruments against the overall sound in the hall (the ambience) and adjusts the processing according to the signal difference detected. A similar adaptive behavior is employed by the performers, who have to adjust certain nuances such as tempo and dynamics according to the sonic output of the electronics. This creates a feedback loop between the performers and the electronics, mediated by the sound and the ambience of the space hosting the two. The separation of the five “interactions” into individual tracks is particularly useful in marking the division between these sections very clearly.

Craquelure (2002) the second piece featured on the CD, consists of two parts of equal duration (also separated into individual tracks), the second being a recasting of the first. The first part consists entirely of pre-recorded crackling sounds and sonic dust created using the composer’s own technique of sound synthesis by iterated nonlinear functions. The second part repeats the same crackling texture, but subjects it to live, room-dependent processing. This live processing is driven mainly by the room’s response to a low-frequency rumbling introduced in the second part to excite the space. The processing results in yet another layer consisting of granular textures that are generally more pronounced than the original (unprocessed) sounds. The same material, therefore, is presented twice, first in its abstract, pre-composed form, then in a live, interactive manner giving it a new identity that is the direct result of the interaction between that original material and the space in which it is being projected.

Audible EcoSystemics, (2002-05) the most recent work included on the present recording, may, in many ways, be considered the culmination of the composer’s work with live electronics. There are currently five sub-pieces (no. 1, nos. 2a and 2b, and nos. 3a and 3b) that share the title Audible EcoSystemics, each with its own subtitle and each examining a specific idea or approach. Of the five pieces in the set, two involve a human performer and three involve only the DSP system. More so than in any of the composer’s other works dealing with live electronics, the space hosting a particular performance is of paramount importance in this set of pieces. In fact, the only interaction or exchange happening is often that between the DSP unit and the space (its response to sounds, its ambience, etc.).

While the system (DSP, performer, etc.) is essentially autonomous, the emphasis in these works is on the semiotic relationship between that system and the space, revealed through a “network of sonic interactions” (Mr. Di Scipio’s homepage, cited 23 September 2005) between the two and mediated by microphones and loudspeakers. Microphones are placed far from the speakers (“close to surfaces or vertices”) in order to hear the overall ambience of the room rather than the direct output of the speakers. In conversation with the composer, he expressed the preference that speakers should be turned to face a wall rather than projected directly at the audience. This is mainly to ensure that, again, more of the ambience is heard and to minimize its being overpowered by sound coming directly from the speakers.

The adaptive, real-time processing is designed in such a way as to ensure that the system is self-regulating. In all five pieces, as the process of exchange or interaction unfolds, it is bound by limits that serve to fine-tune it. These limits will end or “kill” that process if it breaks certain rules. These rules simply ensure equity between all the components of the system and are in place to promote “ecologically sound or biologically consistent relationships” (ibid) between the various components of the system. In other words, they place equal responsibility for sustaining the system on all members of that system. This effectively means that if one component were to behave in a disruptive way (overpowering other components, etc.), that behavior would directly cause the process to end (and start over). This may be caused if a performer does not behave appropriately towards the system (in the context of the pre-defined network of interactions and exchanges) or if the room itself is not responsive. In most cases, disruptive or ecologically unsound behavior is defined in the amplitude and density domains (too high or too low). All this, of course, reflects a personal aesthetic choice on the part of the composer.

Audible EcoSystemics no.1 (Impulse Response Study) involves playing some pulse trains over loudspeakers into a space. These pulses are directly processed by a DSP unit. The manner of processing is adaptive to information that the DSP receives from the microphones, mainly the room’s impulse response to the pulses (and their processing). This, essentially, creates a network of interactions that binds the sounds and their processing to the room’s response to those sounds, that response, of course, being a factor of the sounds themselves. The piece was prepared, in part at the composer’s studio and in part at CCMIX (Center for the Composition of Music Iannis Xenakis) in Paris.

Audible EcoSystemics no.2a (Feedback Study) follows the same basic procedure as no.1 but uses Larsen tones (audio feedback) as its only source material. In order to avoid saturation, the DSP unit is programmed to regulate the levels of the microphones. Here again, the sounds are processed and projected into the space, with information from the resulting sounds being relayed back to the DSP unit via microphones in the space.

Audible EcoSystemics no.2b (Feedback Study, with Vocal Resonances), which is better suited as an installation (and has been presented as such), has a similar setup but incorporates performers. Here, any number of performers (or participants) can “play” the several microphones in the space by creating resonant spaces around them (cupping one’s hands around a microphone, using the mouth to cover all or part of it, etc.). The composer even allows for emitting glottal pulses and “minimal vocal utterances” into the microphone. The present recording features two short excerpts from an installation of the work at the Institute of Psychoacoustics and Electronic Music (IPEM) in Ghent.

Audible EcoSystemics no.3a (Background Noise) and Audible EcoSystemics no.3b (Background Noise, with Glottal Pulses) create perhaps the most fragile and most delicate ecosystem of the set, with the latter reintroducing the element of the live performer. They both rely on even more minimal source material, which is background noise (inside or outside the performance space). This is unusual as most composers often go to great lengths to eliminate that kind of noise. Both studies rely on DSP transformations that are somewhat different from the rest of the set and that are augmented in order to yield significant modifications of the surrounding sonic environment and to transform the noise specific to a space into a very different environment. The addition of a performer in no.3b makes the system even more fragile, as the DSP transformations have to remain essentially the same. In the spirit of equality between all components, the performer has to remain on the same level as background noise. In many respects, this requires performers to behave contrary to how they normally would; it asks them to be invisible, in a sense. The implications of such an approach to performance and rehearsal practices are truly far-reaching both for soloists as well as for ensembles. In fact, the term soloist does not have any real application in this music. All components of the system are equal and share equal responsibility for sustaining that system.

All the pieces featured in this recording are excellent and very compelling sonic representations of their composer’s innovative theoretical ideas. Moreover, they are the sonic records of an ongoing process in which the sonic results and the theories underpinning them evolve simultaneously in a reciprocating fashion, informing and shaping each other. The composer’s treatment of live electronics is quite unique and inventive. The composition process is also a learning process in which the composer, having started with some basic ideas, experiments with and develops these ideas allowing the empirical process to inform and reshape the basic theoretical premises, and vice versa. With some understanding of the principals behind these works, the notion of form as timbre and that the two emerge only in the process of performance becomes evident.

The basic process underlying all these works can be described as balanced reciprocity, a system whose components are all equally responsible for sustaining it. Implicit is another, less obvious reciprocity, which mirrors that of the interactive process. This occurs between form, timbre, and process. It is impossible to clearly and definitively say which of the three is cause and which is effect. All three influence each other in a very dynamic way and evolve together, each shaping the others and, in turn, being shaped by them.

These pieces are, in a very powerful way, true electroacoustic pieces. None of them exist independent of a performance (which in this case simply means an opportunity for the interactions to sonically manifest themselves). This raises an interesting point regarding a recording of these works. Perhaps it should be reiterated that this particular recording presents only a specific instance of the idea or the concept behind each piece and that every performance will change slightly or quite dramatically, in some cases. Despite that, the recording does provide an invaluable sonic record of these ideas and one that is of absolute necessity in the absence of a live performance. It also demonstrates quite convincingly that these works have a profound life beyond the novelty of a live experience. The music on this recording is some of the most innovative, imaginative, and impressive electroacoustic music being created today.