Abstract Representation of Music: A Type-Based Knowledge Representation Framework

The wholesale efficacy of computer-based music research is contingent on the sharing and reuse of information and analysis methods amongst researchers across the constituent disciplines. However, computer systems for the analysis and manipulation of musical data are generally not interoperable. Knowledge representation has been extensively used in the domain of music to harness the benefits of formal conceptual modelling combined with logic based automated inference. However, the available knowledge representation languages lack sufficient logical expressivity to support sophisticated musicological concepts. In this thesis we present a type-based framework for abstract representation of musical knowledge. The core of the framework is a multiple-hierarchical information model called a constituent structure, which accommodates diverse kinds of musical information. The framework includes a specification logic for expressing formal descriptions of the components of the representation. We give a formal specification for the framework in the Calculus of Inductive Constructions, an expressive logical language which lends itself to the abstract specification of data types and information structures. We give an implementation of our framework using Semantic Web ontologies and JavaScript. The ontologies capture the core structural aspects of the representation, while the JavaScript tools implement the functionality of the abstract specification. We describe how our framework supports three music analysis tasks: pattern search and discovery, paradigmatic analysis and hierarchical set-class analysis, detailing how constituent structures are used to represent both the input and output of these analyses including sophisticated structural annotations. We present a simple demonstrator application, built with the JavaScript tools, which performs simple analysis and visualisation of linked data documents structured by the ontologies. We conclude with a summary of the contributions of the thesis and a discussion of the type-based approach to knowledge representation, as well as a number of avenues for future work in this area

Topic Similarity Networks: Visual Analytics for Large Document Sets

We investigate ways in which to improve the interpretability of LDA topic models by better analyzing and visualizing their outputs. We focus on examining what we refer to as topic similarity networks: graphs in which nodes represent latent topics in text collections and links represent similarity among topics. We describe efficient and effective approaches to both building and labeling such networks. Visualizations of topic models based on these networks are shown to be a powerful means of exploring, characterizing, and summarizing large collections of unstructured text documents. They help to "tease out" non-obvious connections among different sets of documents and provide insights into how topics form larger themes. We demonstrate the efficacy and practicality of these approaches through two case studies: 1) NSF grants for basic research spanning a 14 year period and 2) the entire English portion of Wikipedia.Comment: 9 pages; 2014 IEEE International Conference on Big Data (IEEE BigData 2014

In what sense can instruments and bodies be said to form spaces?

My recent work is an exploration of the physical and conceptual mechanisms that interface people with instruments. Central to this investigation is a conception of the performer/instrument assemblage as a symbiosis of two parallel and interdependent systems: one – the performer – moves through space established by the other – the instrument. Each system possesses its own intrinsic properties and characteristics; each possesses capacities to affect and be affected by one another. The music emanates from this contiguous interaction. Instrument surface is understood as a compositional resource itself, a topological façade, defined by ordinal distances, that guides gestures along its contours. Within these fluctuating constellations of spatial coordinates, I consider all the relevant ways a body can move, and establish some general combinatory rules that inform the convergence of forces within the body. The traditional subjects of compositional contemplation such as form, duration, dynamic, etc. are not attributing features to the work per se but emerge as results from spatiotemporal relations of (bodily) movement’s correspondence with (instrumental) surface and mechanism. This liberation of movement is understood as a liberation of timbre, and the inherent indeterminacy of this relationship is embraced. As such, I would hypothesize that sound is, to an extent, freed from the subtractive tendencies of perception that might otherwise subvert it into generalized typological categories. Once liberated from the imagination, sound can bypass the brain and directly engage the nervous system

Compression and communication in the cultural evolution of linguistic structure

Language exhibits striking systematic structure. Words are composed of combinations of reusable sounds, and those words in turn are combined to form complex sentences. These properties make language unique among natural communication systems and enable our species to convey an open-ended set of messages. We provide a cultural evolutionary account of the origins of this structure. We show, using simulations of rational learners and laboratory experiments, that structure arises from a trade-off between pressures for compressibility (imposed during learning) and expressivity (imposed during communication). We further demonstrate that the relative strength of these two pressures can be varied in different social contexts, leading to novel predictions about the emergence of structured behaviour in the wild

Measuring Harmonic Tension in Post-Tonal Repertoire

Despite the large body of research that has examined tonal and atonal harmonies to our perception of tension, there is no work that describes or explores the perception of post-tonal chords, but more specifically, chords that contain both tonal and post-tonal features. This article applies the concept of calculating the total amount of voice-leading movement, to examine its relationship to our perception of tension and release. To do this, three neoclassical pieces are selected to analyze the relationship between theoretical and perceived tension. The findings suggest that in addition to calculating the horizontal motion between harmonies, physical and acoustical factors play a critical role in relating theoretical to perceived tension. This approach is adaptable to other neoclassical works and in addition, this study could have implications in other musical fields such as performance practices and analyzing formal functions in post-tonal repertoire

On the analysis of musical performance by computer

Existing automatic methods of analysing musical performance can generally be described as music-oriented DSP analysis. However, this merely identifies attributes, or artefacts which can be found within the performance. This information, though invaluable, is not an analysis of the performance process. The process of performance first involves an analysis of the score (whether from a printed sheet or from memory), and through this analysis, the performer decides how to perform the piece. Thus, an analysis of the performance process requires an analysis of the performance attributes and artefacts in the context of the musical score. With this type analysis it is possible to ask profound questions such as “why or when does a performer use this technique”. The work presented in this thesis provides the tools which are required to investigate these performance issues. A new computer representation, Performance Markup Language (PML) is presented which combines the domains of the musical score, performance information and analytical structures. This representation provides the framework with which information within these domains can be cross-referenced internally, and the markup of information in external files. Most importantly, the rep resentation defines the relationship between performance events and the corresponding objects within the score, thus facilitating analysis of performance information in the context of the score and analyses of the score. To evaluate the correspondences between performance notes and notes within the score, the performance must be analysed using a score-performance matching algorithm. A new score-performance matching algorithm is presented in this document which is based on Dynamic Programming. In score-performance matching there are situations where dynamic programming alone is not sufficient to accurately identify correspondences. The algorithm presented here makes use of analyses of both the score and the performance to overcome the inherent shortcomings of the DP method and to improve the accuracy and robustness of DP matching in the presence of performance errors and expressive timing. Together with the musical score and performance markup, the correspondences identified by the matching algorithm provide the minimum information required to investigate musical performance, and forms the foundation of a PML representation. The Microtonalism project investigated the issues surrounding the performance of microtonal music on conventional (i.e. non microtonal specific) instruments, namely voice. This included the automatic analysis of vocal performances to extract information regarding pitch accuracy. This was possible using tools developed using the performance representation and the matching algorithm

The morphological and audiative interconnectedness of sound: Equivalence in a multidimensional soundscape

This paper draws on the authorʼs recent theoretical and practical research into the morphology of sound and audiation. In particular, it explores the notion of equivalence in a multidimensional soundscape. Correlations between the interconnectedness of sound-based morphologies emanating from extended guitar techniques and comprehending internal auditory imagination when sound is not physically present will be assessed. To express an all-encompassing mental and visual image of apprehending the value of sound from a morphological and audiative perspective, three-dimensional topological diagrams will be evaluated ‒ a development of previous two-dimensional visualisations. In regard to morphologies, topics of interest are spectromorphology, spatiomorphology, spectral quality, performance space, and performance aspects. Studying these topics will help in the understanding of morphological value. Learning to comprehend morphologies in relation to the listening experience will deepen all round musical abilities. We will therefore investigate audiation through encompassing deep listening, reduced listening, inherent and external qualities, psychological experience, imagination, and improvisation. As more mutual inclusivity is discovered we can start to contemplate more adventurous pedagogical tools from which future nurturing of musicians may be drawn