Edward Braund

Music with Unconventional Computing: Towards a Step Sequencer from Plasmodium of Physarum Polycephalum

The field of computer music has evolved in tandem with advances made in computer science. We are interested in how the developing field of unconventional computation may provide new pathways for music and related technologies. In this paper, we outline our initial work into harnessing the behaviour of the biological computing substrate Physarum polycephalum for a musical step sequencer. The plasmodium of Physarum polycephalum is an amorphous unicellular organism, which moves like a giant amoeba as it navigates its environment for food. Our research manipulates the organism’s route-efficient propagation characteristics in order to create a growth environment for musical/sound arrangement. We experiment with this device in two different scenarios: sample triggering and MIDI note triggering using sonification techniques.

Physarum-Based Memristors for Computer Music

We present results into harnessing the memristive characteristics of Physarum polycephalum for computer music. Memristors are the recently discovered fourth fundamental passive circuit element that relates magnetic flux linkage and charge. Unlike the three established fundamental circuit elements, namely the capacitor, inductor, and resistor, the memristor is non-linear. The plasmodium of Physarum polycephalum is an amorphous unicellular organism that has been discovered to exhibit memristive qualities. We confirm findings that the protoplasmic tube of Physarum polycephalum exhibits memristive properties. We conduct a study that investigates how the memristive qualities of the organism may be used to generate musical responses to seed material. Following on, we briefly present an artefact of our research that takes the form of a piece of music composed for live performance. In the final section, we discuss our future work. Here we offer an insight as to how we plan on expanding the usability of Physarum-based memristors by stabilising the component and overcoming some of the constraints we present within this text.

Music with Unconventional Computing: A System for Physarum Polycephalum Sound Synthesis

The field of computer music is evolving in tandem with advances in computer science. Our research is interested in how the developing field of unconventional computation may provide new pathways for music and music technologies. In this paper we present the development of a system for harnessing the biological computing substrate Physarum Polycephalum for sonification. Physarum Polycephalum is a large single cell with a myriad of diploid nuclei, which moves like a giant amoeba in its pursuit for food. The organism is amorphous, and although without a brain or any serving centre of control, can respond to the environmental conditions that surround it.

BioComputer Music: Generating Musical Responses with Physarum polycephalum-Based Memristors

This paper introduces BioComputer Music, an experimental one piano duet between pianist and plasmodial slime mould Physarum polycephalum. This piece harnesses a system we have been developing, which we call BioComputer. BioComputer consists of an analogue circuit that encompasses components grown from the biological computing substrate Physarum polycephalum. Our system listens to the pianist and uses the memristive characteristics of Physarum polycephalum to generate a musical response that it plays through electromagnets placed on the strings of the piano. Such electromagnets set the strings into vibration, producing a distinctive timbre. Physarum polycephalum is an amorphous unicellular organism that has been discovered to exhibit memristive qualities. The memristor changes its resistance according to the amount of charge that has previously flown through. In this paper, we introduce the general concepts, technology and musical composition behind the BioComputer Music piece. We also discuss our rationale for using Physarum polycephalum.

Experiments in Musical Biocomputing: Towards New Kinds of Processors for Audio and Music

The emerging field of Unconventional Computing is developing new algorithms and computing architectures inspired by or implemented in biological, physical and chemical systems. We are investigating how Unconventional Computing may benefit the future of the music industry and related audio engineering technologies. In this chapter, after a brief introduction to Unconventional Computing, we present our research into harnessing the behaviour of a slime mould called Physarum polycephalum to build new kinds of processors for audio and music. The plasmodium of Physarum polycephalum is a large single cell with a myriad of diploid nuclei, which moves like a giant amoeba in its pursuit for food. The organism is amorphous, and although without a brain or any serving centre of control, can respond to the environmental conditions that surround it. As our research progressed, we have successfully harnessed the organism to implement a sound synthesiser and a musical sequencer, grow biological audio wires, and build an interactive biocomputer that can listen and produce musical responses in real-time.

On Building Practical Biocomputers for Real-world Applications: Receptacles for Culturing Slime Mould Memristors and Component Standardisation

Our application of bionic engineering is novel: we are interested in developing hybrid hardware-wetware systems for music. This paper introduces receptacles for culturing Physarum polycephalum-based memristors that are highly accessible to the creative practitioner. The myxomycete Physarum polycephalum is an amorphous unicellular organism that has been found to exhibit memristive properties. Such a discovery has potential to allow us to move towards engineering electrical systems that encompass Physarum polycephalum components. To realise this potential, it is necessary to address some of the constraints associated with harnessing living biological entities in systems for real-time application. Within the paper, we present 3D printed receptacles designed to standardise both the production of components and memristive observations. Subsequent testing showed a significant decrease in growth time, increased lifespan, and superior similarity in component-to-component responses. The results indicate that our receptacle design may provide means of implementing hybrid electrical systems for music technology.

Music with Unconventional Computing: Granular Synthesis with the Biological Computing Substrate Physarum Polycephalum

This paper reports on the outcomes of an approach to granular synthesis using the biological computing substrate Physarum polycephalum. The plasmodium of Physarum Polycephalum is unicellular with a myriad of diploid nuclei, which moves like a giant amoeba in its pursuit of food. The organism is amorphous, and although without a brain or any serving centre of control, can respond to the environmental conditions that surround it. In the presented approach, we harness the organism’s oscillatory behaviour and protoplasmic network configuration to produce and sequence sound grains. Such an approach is an extension to one of the author’s previous musical works with Physarum polycephalum, which he presented in [13].

A Method for Growing Bio-memristors from Slime Mold

Our research is aimed at gaining a better understanding of the electronic properties of organisms in order to engineer novel bioelectronic systems and computing architectures based on biology. This specific paper focuses on harnessing the unicellular slime mold Physarum polycephalum to develop bio-memristors (or biological memristors) and bio-computing devices. The memristor is a resistor that possesses memory. It is the 4th fundamental passive circuit element (the other three are the resistor, the capacitor, and the inductor), which is paving the way for the design of new kinds of computing systems; e.g., computers that might relinquish the distinction between storage and a central processing unit. When applied with an AC voltage, the current vs. voltage characteristic of a memristor is a pinched hysteresis loop. It has been shown that P. polycephalum produces pinched hysteresis loops under AC voltages and displays adaptive behavior that is comparable with the functioning of a memristor. This paper presents the method that we developed for implementing bio-memristors with P. polycephalum and introduces the development of a receptacle to culture the organism, which facilitates its deployment as an electronic circuit component. Our method has proven to decrease growth time, increase component lifespan, and standardize electrical observations.

An Approach to Building Musical Bioprocessors with Physarum polycephalum Memristors

This chapter presents an account of our investigation into developing musical processing devices using biological components. Such work combines two vibrant areas of unconventional computing research: Physarum polycephalum and the memristor. P. polycephalum is a plasmodial slime mould that has been discovered to display behaviours that are consistent with that of the memristor: a hybrid memory and processing component. Within the chapter, we introduce the research’s background and our motives for undertaking the study. Then, we demonstrate P. polycephalum’s memristive abilities and present our approach to enabling its integration into analogue circuitry. Following on, we discuss different techniques for using P. polycephalum memristors to generate musical responses.

On Unconventional Computing for Sound and Music

Advances in technology have had a significant impact on the way in which we produce and consume music. The music industry is most likely to continue progressing in tandem with the evolution of electronics and computing technology. Despite the incredible power of today’s computers, it is commonly acknowledged that computing technology is bound to progress beyond today’s conventional models. Researchers working in the relatively new field of Unconventional Computing (UC) are investigating a number of alternative approaches to develop new types of computers, such as harnessing biological media to implement new kinds of processors. This chapter introduces the field of UC for sound and music, focusing on the work developed at Plymouth University’s Interdisciplinary Centre for Computer Music Research (ICCMR) in the UK. From musical experiments with Cellular Automata modelling and in vitro neural networks, to quantum computing and bioprocessing, this chapter introduces the substantial body of scientific and artistic work developed at ICCMR. Such work has paved the way for ongoing research towards the development of robust general-purpose bioprocessing components, referred to as biomemristors, and interactive musical biocomputers.