Computational composition strategies in audiovisual laptop performance

We live in a cultural environment in which computer based musical performances have become ubiquitous. Particularly the use of laptops as instruments is a thriving practice in many genres and subcultures. The opportunity to command the most intricate level of control on the smallest of time scales in music composition and computer graphics introduces a number of complexities and dilemmas for the performer working with algorithms. Writing computer code to create audiovisuals offers abundant opportunities for discovering new ways of expression in live performance while simultaneously introducing challenges and presenting the user with difficult choices. There are a host of computational strategies that can be employed in live situations to assist the performer, including artificially intelligent performance agents who operate according to predefined algorithmic rules. This thesis describes four software systems for real time multimodal improvisation and composition in which a number of computational strategies for audiovisual laptop performances is explored and which were used in creation of a portfolio of accompanying audiovisual compositions

"Knowing is Seeing:" The Digital Audio Workstation and the Visualization of Sound

The computers visual representation of sound has revolutionized the creation of music through the interface of the Digital Audio Workstation software (DAW). With the rise of DAW-based composition in popular music styles, many artists sole experience of musical creation is through the computer screen. I assert that the particular sonic visualizations of the DAW propagate certain assumptions about music, influencing aesthetics and adding new visually-based parameters to the creative process. I believe many of these new parameters are greatly indebted to the visual structures, interactional dictates and standardizations (such as the office metaphor depicted by operating systems such as Apples OS and Microsofts Windows) of the Graphical User Interface (GUI). Whether manipulating text, video or audio, a users interaction with the GUI is usually structured in the same mannerclicking on windows, icons and menus with a mouse-driven cursor. Focussing on the dialogs from the Reddit communities of Making hip-hop and EDM production, DAW user manuals, as well as interface design guidebooks, this dissertation will address the ways these visualizations and methods of working affect the workflow, composition style and musical conceptions of DAW-based producers

On the synthesis and processing of high quality audio signals by parallel computers

This work concerns the application of new computer architectures to the creation and manipulation of high-quality audio bandwidth signals. The configuration of both the hardware and software in such systems falls under consideration in the three major sections which present increasing levels of algorithmic concurrency. In the first section, the programs which are described are distributed in identical copies across an array of processing elements; these programs run autonomously, generating data independently, but with control parameters peculiar to each copy: this type of concurrency is referred to as isonomic}The central section presents a structure which distributes tasks across an arbitrary network of processors; the flow of control in such a program is quasi- indeterminate, and controlled on a demand basis by the rate of completion of the slave tasks and their irregular interaction with the master. Whilst that interaction is, in principle, deterministic, it is also data-dependent; the dynamic nature of task allocation demands that no a priori knowledge of the rate of task completion be required. This type of concurrency is called dianomic? Finally, an architecture is described which will support a very high level of algorithmic concurrency. The programs which make efficient use of such a machine are designed not by considering flow of control, but by considering flow of data. Each atomic algorithmic unit is made as simple as possible, which results in the extensive distribution of a program over very many processing elements. Programs designed by considering only the optimum data exchange routes are said to exhibit systolic^ concurrency. Often neglected in the study of system design are those provisions necessary for practical implementations. It was intended to provide users with useful application programs in fulfilment of this study; the target group is electroacoustic composers, who use digital signal processing techniques in the context of musical composition. Some of the algorithms in use in this field are highly complex, often requiring a quantity of processing for each sample which exceeds that currently available even from very powerful computers. Consequently, applications tend to operate not in 'real-time' (where the output of a system responds to its input apparently instantaneously), but by the manipulation of sounds recorded digitally on a mass storage device. The first two sections adopt existing, public-domain software, and seek to increase its speed of execution significantly by parallel techniques, with the minimum compromise of functionality and ease of use. Those chosen are the general- purpose direct synthesis program CSOUND, from M.I.T., and a stand-alone phase vocoder system from the C.D.P..(^4) In each case, the desired aim is achieved: to increase speed of execution by two orders of magnitude over the systems currently in use by composers. This requires substantial restructuring of the programs, and careful consideration of the best computer architectures on which they are to run concurrently. The third section examines the rationale behind the use of computers in music, and begins with the implementation of a sophisticated electronic musical instrument capable of a degree of expression at least equal to its acoustic counterparts. It seems that the flexible control of such an instrument demands a greater computing resource than the sound synthesis part. A machine has been constructed with the intention of enabling the 'gestural capture' of performance information in real-time; the structure of this computer, which has one hundred and sixty high-performance microprocessors running in parallel, is expounded; and the systolic programming techniques required to take advantage of such an array are illustrated in the Occam programming language

Interactive Musical Partner: A System for Human/Computer Duo Improvisations

This research is centered on the creation of a computer program that will make music with a human improviser. This Interactive Musical Partner (IMP) is designed for duo improvisations, with one human improviser and one instance of IMP, focusing on a freely improvised duo aesthetic. IMP has Musical Personality Settings (MPS) that can be set prior to performance, and these MPS guide the way IMP responds to musical input from the human. The MPS also govern the probability of particular outcomes from IMP’s creative algorithms. IMP uses audio data feature extraction methods to listen to the human partner, and react to, or ignore, the human’s musical input, based on the current MPS. This course of research presents a number of problems. Parameters for the Musical Personality Settings (MPS) must be defined, and then those parameters must be mapped to extractable audio features. A system for musical decision-making and reaction/interaction (action/interaction module) must be in place, and a synthesis module that allows for MPS control must be deployed. Designing a program intended to play with an improviser, and then improvising with that program has caused me to assess every aspect of my practice as an improviser. Not only has this research expanded my understanding of the technologies involved and made me a better technologist, but striving to get the technology to be musical has made me look at all sides of the music I make, resulting in a better improvising artist

Syncopation and the Score

The first and second authors were supported by an EPSRC DTA (www.epsrc.ac.uk) studentship

Mutations (megamix): exploring notions of the ‘DJ set’, ‘mashup’ and ‘remix’ through live piano-based performance

Mutations (megamix) is an interactive work for piano and electronics, which explores notions of the “DJ set”, “mashup” [1. The term “mashup” is used within popular music to denote a specific compositional technique in which two or more existing records are superimposed to create a new track. This often involves the use of vocal a capella material, which is layered against other recordings

Mutations (megamix): exploring notions of the ‘DJ set’, ‘mashup’ and ‘remix’ through live piano-based performance

Mutations (megamix) is an interactive work for piano and electronics, which explores notions of the “DJ set”, “mashup” [1. The term “mashup” is used within popular music to denote a specific compositional technique in which two or more existing records are superimposed to create a new track. This often involves the use of vocal a capella material, which is layered against other recordings

Loop assembly: a simple and open system for recursive fabrication of DNA circuits.

High efficiency methods for DNA assembly have enabled routine assembly of synthetic DNAs of increased size and complexity. However, these techniques require customisation, elaborate vector sets or serial manipulations for the different stages of assembly. We have developed Loop assembly based on a recursive approach to DNA fabrication. The system makes use of two Type IIS restriction endonucleases and corresponding vector sets for efficient and parallel assembly of large DNA circuits. Standardised level 0 parts can be assembled into circuits containing 1, 4, 16 or more genes by looping between the two vector sets. The vectors also contain modular sites for hybrid assembly using sequence overlap methods. Loop assembly enables efficient and versatile DNA fabrication for plant transformation. We show construction of plasmids up to 16 genes and 38 Kb with high efficiency (>80%). We have characterized Loop assembly on over 200 different DNA constructs and validated the fidelity of the method by high-throughput Illumina plasmid sequencing. Our method provides a simple generalised solution for DNA construction with standardised parts. The cloning system is provided under an OpenMTA license for unrestricted sharing and open access. This article is protected by copyright. All rights reserved.Support for the authors was provided by Becas Chile and the Cambridge Trust (to B.P.), University of Cambridge BBSRC DTP programme (to M.D.), and the Biotechnology and Biological Sciences Research Council and Engineering and Physical Sciences Research Council [OpenPlant Grant No. BB/L014130/1] (to N.P., F.F. and J.H.). Laboratory automation, nextgeneration sequencing and library construction was delivered via the BBSRC National Capability in Genomics (BB/CCG1720/1) at Earlham Institute. F.F. acknowledges funding from CONICYT Fondecyt Iniciación 11140776. F.F. and R.A.G. acknowledge funding from Fondo de Desarrollo de Areas Prioritarias (FONDAP) Center for Genome Regulation (15090007) and Millennium Nucleus Center for Plant Systems and Synthetic Biology (NC130030)