This article invites reflection on the ambiguity of sonic temporalities as the lines between physicality and immediacy become increasingly blurred. Through the notion that digital technologies are haunted by analogic process, I foreground the concept of Palimpsestic Listening to explore the musical qualities and critical resonances of sonic acts and objects in hybrid physical/digital systems that evoke layered temporalities that are ‘historically distinct nonetheless linked’. I also seek to illustrate the significance of engaging practically with this concept by discussing the methods behind my composition D/ta Ro} – A Dialectical Trash Heap, a sound installation that interrogates the relationship between sonic materiality and digital audio processing and how acts of erasure and time-stretching might influence the layering of disparate sound materials.

Drawing on François-Bernard Mâche’s writings as well as interviews and analyses by musicologists, this paper tries to describe how his music may be described as ‘sacred’ music, however devoid of any religious aspects, and what this implies for us as listeners and/or as artists. To Mâche, the sacred is the consideration of a specific relationship to the world as the object and as the subject, as the ‘why’ and as the ‘how’ of music. Musical examples from his mixed music and acousmatic music illustrate how Mâche goes from his theories to more practical aspects of his compositional technique and listening behaviours.

Shared music improvisation constitutes a formidable vector for intersubjective connection. Improvisation is a space of non-semantic communication that allows for putting oneself at risk and requires mutual trust and listening, as well as dialogical qualities. This article investigates the intersubjective dimension of improvisation in electronic music praxis, focusing on how the electronic medium can be used to foster mediation between musicians. The article builds on a practice-based enquiry in duo format, conducted in three successive technological settings, with a methodological entanglement of aesthetic and design aims. Systematic video documentation and participant observation provide an analytical counterpoint to an immersion in the improvisatory praxis. A set of design strategies for fostering intersubjective connection in shared musicianship emerges from the research. The findings provide the basis for a dialectical consideration between musical and intersubjective aesthetics. The discussion points to the diversity of social functions of music and their respective aesthetics. Electronic instruments’ inherent plasticity allows for reconfiguring the social space of music-making, and thus opens perspectives for devising synergetic music systems that emphasise an ethos of shared agency over the production of musical objects or performances.

This article reflects on how personal digital musical instruments evolve and presents an augmented violin developed and performed by the author in improvised performance as an example. Informed by the materialism of Gilles Deleuze and Felix Guattari, an image of ‘flows of inhomogeneous matter’ provokes reflection on a mode of production common to artisanal craftmanship and digital lutherie alike, namely the pre-reflective skilfulness negotiating the singularities of inhomogeneous matter with the demands of the production – a process which itself may be thought of as im-pro-visation (‘un-fore-seen’). According to Gilbert Simondon, all technical objects develop in this way: functional interdependency emerges when abstractly ideated elements begin to enter into unanticipated synergistic relationships, suggesting a material logic dependent on unforeseen potentialities. The historical development of the acoustic violin exemplifies such an evolution, with, like all technical objects, additional latent potential. Digital artists can work like artisanal craftsmen in tinkering with technical elements, teasing out their synergies through abductive, trial-and-error experimentation. In the context of developing digital musical instruments, model-free design of real-time digital signal processing symmetrising action and perception yields highly refined results. Like musical improvisation – constrained by time – improvised development of these instruments turns the material obstacles into their very means of realisation.

In this article I describe the development of a performance practice with a new electroacoustic instrument – the FAAB (feedback-actuated augmented bass). Drawing on a background in improvisation, I discuss how the feedback-induced behaviour of the instrument sets it apart from an acoustic bass and how the implementation of operationally closed digital signal processing algorithms facilitates greater systemic autonomy. In identifying resistance as a key feature of improvisation, I propose the term ‘diachronic mastery’ as a way of addressing the equilibration of sensorimotor schemes in the context of developing a performance practice with a complex hybrid system such as the FAAB. Through a discussion of the term ‘agency’ as it appears in recent literature, I develop a preliminary framework for addressing both the immediate experience of agency emerging in performance ecosystems and the biologically informed definition of the term that may be useful in the design of increasingly autonomous instruments and performance systems.

Contemporary thought is moving away from the notion that the human is a clear-cut concept. In particular, non-anthropocentric views are proliferating within the interdisciplinary area of critical post-humanism, with emphasis on non-dualistic views on relations between human and technology. This article shows how such a view can inform electroacoustic and computer music practice, and sees improvisation linked with composition as a fruitful avenue in this. Following a philosophical preparation and a discussion of relevant music discourse, two computer music works created by the author are discussed to demonstrate a model of music-making that merges composition and improvisation, based on the concepts of cognitive assemblages and intra-action, following the writings of N. Katherine Hayles and Karen Barad, respectively. The works employ techniques related to artificial intelligence and cybernetics, such as machine learning algorithms, agent-based organisation and feedback systems. It is argued that acousmatic sound is an important aspect of this practice. The research is thus situated not only in the frames of improvisation practice and music technology but also within spatial acousmatic composition and performance.

This article documents the processes behind our distributed musical instrument, Ambiguous Devices. The project is motivated by our mutual desire to explore disruptive forms of networked musical interactions in an attempt to challenge and extend our practices as improvisers and instrument makers. We begin by describing the early design stage of our performance ecosystem, followed by a technical description of how the system functions with examples from our public performances and installations. We then situate our work within a genealogy of human–machine improvisation, while highlighting specific values that continue to motivate our artistic approach. These practical accounts inform our discussion of tactility, proximity, effort, friction and other attributes that have shaped our strategies for designing musical interactions. The positive role of ambiguity is elaborated in relation to distributed agency. Finally, we employ the concept of ‘feedthrough’ as a way of understanding the co-constitutive behaviour of communication networks, assemblages and performers.

We explore the tree limits recently defined by Elek and Tardos. In particular, we find tree limits for many classes of random trees. We give general theorems for three classes of conditional Galton–Watson trees and simply generated trees, for split trees and generalized split trees (as defined here), and for trees defined by a continuous-time branching process. These general results include, for example, random labelled trees, ordered trees, random recursive trees, preferential attachment trees, and binary search trees.

This paper focuses on quality assurance in language massive open online courses (LMOOCs). It is a qualitative study that adopts the grounded theory method and analyses evaluative comments on the quality of LMOOCs from learners’ perspectives. With the data collected from 1,000 evaluations from English as a second language (ESL) learners on China’s biggest MOOC platform “iCourse”, this study examines what has influenced learners’ perceptions of LMOOCs and identifies the specific quality criteria of five types of them, including ESL courses for speaking, reading, writing, cultural studies, and integrated skills. The results of the study will lay a foundation for the establishment of a quality criteria framework for LMOOCs and provide insights into design principles for effective online language courses tailored to the diverse needs of a massive number of language learners.