2. GROUP IMPROVISATION

Improvisation, in music as elsewhere, is a precarious process. Improvisation in music is most often invoked in the mutually enabling relationship between a human performer and their environment, the latter being partly constituted of, as well as co-inhabited by, other performers. Following Maturana and Varela, I will define such a relationship as structurally coupled, that is, constituted by ‘a history of recurrent interactions between two (or more) systems’ (Reference Maturana and Varela1980: 75). A precondition for the structural coupling of living systems is their operational closure, defined by Di Paolo etal. as ‘a network of precarious processes in which each process enables at least one other process in the system and is, in turn, enabled by at least one other process in the system’ (2017: 113). Consequently, operational closure is a prerequisite for systemic self-individuation, understood to be the ability of the system to define itself against its environment through the continuous production of a boundary without which it would become assimilated by that environment (Varela Reference Varela and Tauber1991).

The openness required by structural coupling comes at a price: whether observed at the level of the individual agent or network-level of interacting agents and their environments, precarious relationships between far-from-equilibrium systems are the norm. We can see how this applies to the process of group improvisation: in order to facilitate interaction and hence sustain the improvisational process, the improviser needs to retain a structurally coupled relationship to their environment, including other improvisers. At the same time, merely adopting or mimicking the behaviour of other performers, or even the group, without somehow modulating the coupling to these, undermines the dynamics of improvisation. Reminiscing about the weekly improvisation meeting The Gathering, Maggie Nicols (in Rose Reference Rose2017: 73–4) explains: ‘you’d get a period where it would be the same people and it would get incredibly coherent, almost insular, almost to the point where it was stagnating. And then somebody would come who would just completely disrupt everything – but it kept it fresh.’ Here, the maverick improviser defines themself against their sonic environment, disrupting the equilibrium and hence maintaining the openness of the improvisation. In Rose’s words: ‘the process of improvisation develops and benefits through not being too tied to one way of doing things. This not fixed, potential instability gives rise to creativity and new opportunities within the continuum of the activity’ (Rose Reference Rose2017: 74).

If indeed improvisation happens in the structurally coupled relationship between operationally closed agents and their environments, it follows that improvisation is not an essence of these agents but an emergent property of their relationships (Loaiza Restrepo Reference Loaiza Restrepo2018: 164). The social dynamics of group improvisation are sustained through this non-equilibrium and as such, the oft-used term ‘playing together’ does not do justice to what is essentially a precarious and open-ended process of equilibrating asynchronous relationships between individual agents. Experiencing group improvisation (from both a performer and an audience perspective), it is often evident how such relationships play out: conscious and pre-reflective intentionalities and actions of individuals as well as the affordances of the environment (Gibson Reference Gibson1979) and instruments are continuously negotiated and equilibrated at a number of time scales. In this article I will focus on performer–instrument relationships, first in the context of acoustic instruments and later in a discussion of how improvisation manifests in the relationship with a feedback double bass.

3. THE SOLO IMPROVISER

Drawing on Judith Butler’s work, in his discussion of group improvisation, Stapleton writes: ‘It [improvisation] requires a willingness to risk one’s values … to give up a stable understanding of identity, to risk one’s very being, in responding to the address of another’ (2013: 172). In the case of a solo performance, the enactment of improvisation, in the absence of another, may be less evident. If improvisation is enacted and relational rather than intrinsic and presupposes an agent open to environmental perturbances, then we need to understand how a precarious scheme may be established in a solo practice.

Quoted in Borgo (Reference Borgo, Siddall and Waterman2016), in Phil Hopkin’s film Amplified Gesture, Evan Parker states:

Parker’s use of the teaching analogy and his description of loss of control aligns with Di Paolo etal.’s development of a sensorimotor agency model:

For equilibration and hence improvisation to be possible, the relationship between performer and instrument must rely on a precarious and metastable learning agent (in this case the performer) coupled to an environment (here the instrument), the control over which can never be total. Why stability can only be temporary, not just in improvisation, but in so many other instances of life, may be illustrated through Heinz von Foerster’s order from noise principle (von Foerster Reference Von Foerster2003: 11); briefly, this principle states that a self-organising system depends on a supply of entropy in the shape of ‘cheap, undirected energy’ (ibid.: 13) from its environment, without which the system will be unable to adapt to changes in that very same environment. In the case of an improvised solo performance, the instrument not only translates musical ideas and gestures into sound waves but, in constituting an environment, also perturbs the stability of the performer, causing them to reconfigure their sensorimotor states through a process of self-organisation similar to that of group improvisation where ‘critical levels of complexity, responsiveness, and surprise can be reached and maintained over the course of an extended performance’ (Borgo Reference Borgo2005: 81). Edgar Landgraf observes that ‘improvisation and the overall incorporation of contingent elements inject “noise” into the system: they provide a resource pool from which the system can draw new impulses to create new forms and build new structures’ (Landgraf Reference Landgraf, Clarke and Hansen2009: 188). As such, the instrument, rather than being a transparent technology for the performer’s self-expression, is intrinsically tied to the musical process and outcome (see also Mudd Reference Mudd2017: 59 and Di Scipio Reference Di Scipio1998). I will argue that this contribution happens through a degree of resistance, defining the structurally coupled, asymmetrical and precarious relationship between an operationally closed system and its environment, that is, performer and instrument.

In my own acoustic solo practice, resistance is a key factor in establishing precarious relationships that challenge my own physical abilities as well as those of the double bass. The instrument is set up with a very high action (string height from fingerboard) and stiff steel strings, meaning that a large amount of physical effort is needed in order to project sound. What is gained is a highly resonant, responsive and lively instrument, the interaction with which leaves a fairly wide margin for unintended yet welcome sonic artefacts such as buzzing and string slipping (Melbye Reference Melbye2014). Exactly such artefacts constitute the noise that drives the self-organisation of sensorimotor agency: through my coupling with the double bass, such ‘slips’ or unintentional events become the entropy that pushes me out of my internal stability or comfort zone and elicits responses that equilibrate between intention and outcome. It is in this unstable and precarious space that solo improvisation unfolds.

Rather than being understood as a hindrance to the true intentions of an agent, resistance co-defines and enables improvisation in the same way that gravity is a precondition for, and not a hindrance to, Olympic weightlifting: the performer physically engages the instrument and explores its and their own physical limits while sometimes, as in the case of Evan Parker, pushing the shared understanding of what these limits may be.

4. THE FAAB: A FEEDBACK-ACTUATED AUGMENTED BASS

As a double bass player, composer and improviser, I rely on the vast frequency range and physical power of the instrument, combined with the development of a vocabulary of extended techniques for bowing, plucking and preparations. While this acoustic practice affords many additional years (if not lifetimes) of exploration, it has spawned an investigation into how certain sonic features and behaviours may manifest in an instrument with an increased autonomous response, actuated and governed by forces operating outside the domain of my immediate agency.

In other words, my wish has been to explore how salient properties of my playing may become transported and mediated through a self-oscillating feedback instrument, partly actuated and driven by a force other than myself. In previous work, I have explored the double bass body as a self-actuating phenomenon (Melbye Reference Melbye2019) whereas with the current project, the strings take centre stage.

The FAAB was developed in collaboration with Halldór Úlfarsson, whose cello-like feedback instrument the halldorophone (Úlfarsson Reference Úlfarsson2018, Reference Úlfarsson2019) has been adopted by both composers and performers. Similar design strategies have been deployed (also in collaboration with Úlfarsson) by Alice Eldridge and Chris Kiefer (Eldridge and Kiefer Reference Eldridge and Kiefer2017) and Thanos Polymeneas-Liontiris (Reference Polymeneas-Liontiris2018). Briefly, the FAAB is a double bass equipped with a pickup placed under each individual string, the signals of which are sent to a microprocessor. The output is then sent to an amplifier driving a speaker embedded in the back of the instrument.

The nature of the coupling between the electronics and the instrument is such that as the system’s amplitude is increased, the speaker mechanically vibrates the double bass body and consequently the strings, causing them to enter into self-oscillation (feedback). A technically involved discussion of the FAAB has been published elsewhere (Úlfarsson and Melbye Reference Úlfarsson and Melbye2020), while Movie Example 1 documents an improvisation with the instrument.

4.2. Accommodating technique

Feedback systems are by no means new (Sanfilippo and Valle Reference Sanfilippo and Valle2013; Sanfilippo Reference Sanfilippo2019) but what sets the FAAB apart is the implementation of mechanical and digital feedback in a culturally highly defined instrument such as the double bass (Figures 1 and 2; see also Eldridge and Kiefer Reference Eldridge and Kiefer2017; Úlfarsson Reference Úlfarsson2019). The double bass has co-evolved with musical idioms, repertoires and techniques that can fundamentally be mastered. Consequently, the physical demands of the instrument, while being exploited for their spectral richness, have traditionally been something to overcome. With the previous discussion of resistance and diachronic mastery in mind, I will here attempt an account of the development of two specific techniques that embrace the inherent resistance and non-linearity of the FAAB. While these are more or less established techniques in the vocabulary of contemporary double bass playing (Thelin Reference Thelin2009; Dresser Reference Dresser2010), the way they manifest when applied to the FAAB is significantly altered by the adaptive and precarious processes of the instrument.

Bowed multiphonics are caused by a combination of bow pressure, speed, position and light left-hand fingering, causing the emergence of a complex harmonic spectrum (Thelin Reference Thelin2011). Previously, I have used multiphonics in both improvised and composed settings to induce spectral variation and ambiguity in single-string pitches. Since I am generally interested in variation and, to a certain extent, instability of harmonic and inharmonic spectra, the FAAB offers an exciting environment for working with multiphonics. Through variations in bow pressure and left-hand dampening and position, the feedback-induced self-oscillation of the string will contribute to the complication of stick-slip relationships, almost reversing the bowing process to that of the string bowing the bow. Further increasing bow pressure and slowing bow speed close to the point of arresting string oscillation results in interesting phase resets of the string’s oscillation pattern, akin to the string having hiccups (Movie Example 2).

Because of the fact that the FAAB is often in a state of mechanical excitement, what has traditionally been a largely monophonic instrument is now a potential four-voice continuous resonator. The manual actuation of any single string will often be accompanied by the phenomenon of one or more of the other three strings feeding back, and while this may in some cases be musically desirable, the continuous shifting between four open-string drones easily becomes tedious. Consequently, I have needed to accommodate my left-hand technique to either dampening unwanted resonating strings or fingering pitches on those strings in order to create chords in addition to the intentionally bowed or plucked pitch. As an extension of this, using both hands for stopping strings has proven to be a very useful approach to generating chords with asynchronous individually blooming pitches. With this technique I can access an increased pitch range, creating sustained chordal textures beyond the range of conventional bass playing and allowing me to additionally explore beatings and interference between individual as well as clusters of pitches (Movie Example 3).

The DSP processes embedded in the feedback loop add an additional layer of complexity and interactivity to the system: adaptive filters will cause the spectral balance to shift in accordance with time-variant frequency and amplitude changes and as such, not only depend on the current state of the system, but also its history (hysteresis). Since the parameters controlling these processes are largely a function of the system state itself, my main access to them is through physical interactions with the instrument that now doubles as a detailed and non-linear DSP-interface (the control interface visible in Figure 1 only controls individual string volume and processing blend). As such, my interactions with the system have far-reaching and sometimes unpredictable consequences in both the digital and physical domains, in the latter case exemplified through the complex relationship between strings and bow. While these digital and physical domains phenomenologically ultimately fuse into a single perceptual object, to a certain extent they can performatively be engaged as discrete processes, thereby offering the performer the opportunity to engage with a variety of systemic granularities. For example, the centre frequencies of a bank of band-pass filters are modulated by the difference between instantaneous and running-mean string amplitude analysis, meaning that a steady increase in bow pressure will leave the filter response largely stable, while any sudden amplitude fluctuation, be it an increase or a sudden drop (e.g., caused by decoupling the bow from the string), will cause an accumulating increase in overall inharmonicity followed by a slow decay. While hysteresis manifests in acoustic phenomena such as the phase-locking occurring in multiphonics (Thelin Reference Thelin2011: 2), the extended digital working memory of the FAAB allows for me to engage and improvise with the instrument in an expanded temporal field.

Figure 1. The FAAB, front.

Figure 2. The FAAB, back.

5. AGENCY

In recent post-humanist literature, agency is a frequently used term often assigned to humans and objects alike, as when Jane Bennett addresses ‘the deceit that humanity is the sole or ultimate wellspring of agency’ (Bennett Reference Bennett2010: 30) or Karen Barad, tracing agency’s wellspring to relational properties, states that ‘agency is a matter of intra-acting; it is an enactment, not something that someone or something has’ (Barad Reference Barad2007: 178). In writings on music and sound art, this relational attitude towards agency is often reflected in suggestions that the tools of the artist contribute to the enactment of an artwork different from the intentionality of the performer. An example is found in Tom Davis’s discussion of the Feral Cello (Davis Reference Davis2017): after an informative overview of agency in practice and theory, Davis concludes that ‘We have reached a place where agency is not an attribute that is possessed by an object, be that human or machine. Rather agency is something that arises in activity in the moment’ (ibid.: 280). However, only pages later he mentions ‘the agency of the cello’ (ibid.: 282) only to return to ‘a single performer/cello/machine system with mutable boundaries, both in terms of agency and subjectification’ (ibid.: 282). Here it is not clear if agency is in fact emergent and enacted – a relational property – or whether it can be attributed to a specific part – human, machine or cello – of the system. Agency, through mutable boundaries, almost seems to become a deus ex machina: a mystical force akin to the idea of the social criticised by Bruno Latour (Reference Latour2005: 97).

On the Humanising Algorithmic Listening project’s blogFootnote ¹ Alice Eldridge (Reference Eldridge2017) and Paul Stapleton (Reference Stapleton2017) both make use of the term ‘human-machine agency’. Without further clarification, it is difficult to pinpoint the authors’ exact meaning of the term, which is possibly intentional. The hyphen in the terminology suggests that agency is an emergent property of the human-machine assemblage, which seems to be supported by Stapleton’s additional use of the term ‘distributed agency’ (Stapleton Reference Stapleton2017; see also Stapleton, Waters, Ward and Green Reference Stapleton, Waters, Ward and Green2016). It may simply be that agency is defined along the lines of a Latourian actor, that is, ‘any thing that does modify a state of affairs by making a difference is an actor – or, if it has no figuration yet, an actant’ (Latour Reference Latour2005: 71). This resonates with a folk-psychological understanding of agency, which finds its philosophical exposition in Dennett’s Intentional Stance (Dennett Reference Dennett1987). But if agency is a purely perceived property of humans, objects, systems, relationships and possibly even ideas, then we run the danger of reducing it to a vague term that begs the question: is there anything that doesn’t have agency?

David Borgo is patently aware of the danger of flattening ontology to the extent that agency loses its meaning (Borgo Reference Borgo, Siddall and Waterman2016: 114), and instead turns to the term ‘interagency’ to describe human–machine relationships that are mutually co-defining in music performance. Here, Borgo follows Rammert (Reference Rammert2008), who identifies three types of interagency: Interaction between human actors, Intra-activity between technical agents and Interactivity between people and objects (ibid.: 119). As such, Rammert avoids an ontological discussion of the term in favour of ‘questions of empirical changes and practical consequences’ (ibid.: 115). Borgo’s comparison of Actor-Network-Theory (see also Latour Reference Latour2005) with neocybernetics is very relevant and importantly draws attention to the epistemological implications of how complex networks are traced in both theories. Yet, while the structural coupling of neocybernetics is fundamentally tied to the operational closure of a system with a distinct boundary, Latour’s ontologically flat networks comprise actors with no depth beyond that engendered by their relations and as such compromise the property of self-individuation crucial for self-organisation.Footnote ²

Similarly, for Sanfilippo and Di Scipio (Reference Sanfilippo and Di Scipio2017) agency is related to neocybernetics and defined through processes of operational closure and structural couplings – two features that Borgo also requires for interagency (Borgo Reference Borgo, Siddall and Waterman2016: 119). While the authors take great pains to define the term ‘autonomy’ (Sanfilippo and Di Scipio Reference Sanfilippo and Di Scipio2017: 22), in their definition of agency however, even automated stochastic processes seem to constitute an agent (ibid.: 2).

In his important paper ‘Performance Ecosystems: Ecological Approaches to Musical Interaction’, Simon Waters, although employing the terms ‘machinic agency’ and ‘shared agency’ (Waters Reference Waters2007: 10, 7), points to the epistemological shaky ground from which such definitions arise:

Waters draws attention to the opaque use of agency that often accompanies the acknowledgement that something certainly does change when we interact with computers and complex systems. While there has historically been an ontologically unjustifiable tendency to reserve agency to humans, I believe that simply granting it to an observed feature of complex systems and relationships ignores the diversity of these phenomena and the levels of their interactions, a problem that Rammert (Reference Rammert2008) goes a long way to addressing. However, following Barandiaran etal.’s call for a ‘generative definition of agency’ (Barandiaran, Di Paolo and Rohde Reference Barandiaran, Di Paolo and Rohde2009: 369) in cognitive science, I believe that the community of musicians, sound artists and instrument designers may benefit from a discussion of what constitutes agency in the first place. If we simply say that the machine has agency and assume it to be a heuristic rather than an operational discussion, we may imbue the machine with a perceived agency, but the intentional stance will still be a property of the human perceiver. If, on the other hand, we choose to locate distributed agencies in the relations between biological and non-biological systems, I believe that we will still need to pose the question of what causes those agencies to emerge and whether the presence of human or biological agents is in fact the condition for minimal agency in these relationships. Only then can we move from the descriptive to a generative and explanatory definition of agency as a basis for a discussion of the use of the term with regard to both the creation of, and the interaction with, complex performance systems.

In the book Sensorimotor Life: An Enactive Proposal, Di Paolo etal. propose a definition of agents and agency that Meincke (Reference Meincke and Schurz2018) refers to as bio-agency:

According to Di Paolo etal., agency must fulfil three mutually enabling conditions: self-individuation, interactional asymmetry and normativity. Self-individuation is understood to be a process that relies on the continuous self-production of the physical boundaries between the system and its environment (ibid.: 154, see also Thompson Reference Thompson2007: 98), interactional asymmetry describes the ability of the system to modulate its coupling with the environment (Di Paolo etal. Reference Di Paolo, Buhrmann and Barandiaran2017: 117), while normativity is the ability of the system to act according to its own intrinsic desires or goals (ibid.: 120). While interactional asymmetry emerges in several contemporary feedback systems, the claim that current artificial systems exhibit normative behaviour is challenged by both Di Paolo etal. (ibid.: 178) and Thompson (Reference Thompson2007: 260). The question here is to which extent normative behaviour can be ascribed to a system whose goals are defined by the designer rather than by the system itself. In the case of complex audio feedback systems designed for improvisation and thus exhibiting behaviour not strictly tied to an end-goal, the answer is not straightforward and calls for further investigation.Footnote ³ As the first condition, self-individuation necessitates the continuous production of a boundary towards the agent’s environment (Di Paolo etal. Reference Di Paolo, Buhrmann and Barandiaran2017: 116) and, as such, may be the most difficult condition for artificial systems to fulfil, requiring the establishment of a far-from-equilibrium – and possibly biological – system.

Through this brief overview of the subtle arguments of Di Paolo etal., what becomes clear is that bio-agency is not exclusive to humans or even self-aware organisms; a living cell is an agent (ibid.: 130). Yet, observed complex behaviour is not sufficient either. However, bio-agency does not do justice to the felt sense of agency that musicians and improvisers encounter when co-constituting complex performance ecologies. In our immediate musical interactions, we will probably ascribe more agency to the FAAB than we would, for example, to sourdough, even though the latter qualifies for bio-agency while the former does not. Consequently, I propose to adopt an epistemology that embraces the understanding of both interagency as it emerges in the relational domain of organisms and objects and bio-agency as a property of operationally closed, self-individuating and normative systems. This epistemology would embrace a top-down approach (interagency) for the understanding of performance ecosystems, structural couplings and assemblages, as well as bio-agency as a bottom-up explanation of what constitutes minimal agency as a property of operationally closed and self-individuating systems. Having two definitions of a single term may seem confusing but reflects the tension inherent in the relationship between immediate musical encounters and analytical discourse which is the reality for many performers, composers and instrument-builders, such as those constituting the NIME (New Interfaces for Musical Expression) community. I believe that we can sustain the duality of the term through an increased clarity about which agencies are at play. As such, each definition, interagency and bio-agency, may ultimately help elucidate properties of the other, while nodes of intersection will emerge. As an example, I will suggest that interactional asymmetry in the individual (bio-agential) domain translates to minimal interagency in the relational domain, the latter understood to be the asymmetrical relationship between (non-biological) objects, such as two instruments or performance systems interacting.

As a design goal, bio-agency is admittedly ambitious, yet in a time where AI and genetic algorithms are ubiquitous in new instrument designs (Fiebrink Reference Fiebrink2011; Eldridge and Bown Reference Eldridge, Bown, McLean and Dean2018), there is nothing preventing us from seeking inspiration in and pursuing other biological and cognitive theories. Here, evolvable hardware (Di Paolo etal. Reference Di Paolo, Buhrmann and Barandiaran2017: 172) and Gordon Pask’s remarkable Ear (Cariani Reference Cariani1993) represent fascinating endeavours that may be worth pursuing further in the ongoing process of creating complex performance ecosystems with multiple agencies, biological as well as non-biological.