Towards the Automatic Analysis of Metric Modulations

PhDThe metrical structure is a fundamental aspect of music, yet its automatic analysis from audio recordings remains one of the great challenges of Music Information Retrieval (MIR) research. This thesis is concerned with addressing the automatic analysis of changes of metrical structure over time, i.e. metric modulations. The evaluation of automatic musical analysis methods is a critical element of the MIR research and is typically performed by comparing the machine-generated estimates with human expert annotations, which are used as a proxy for ground truth. We present here two new datasets of annotations for the evaluation of metrical structure and metric modulation estimation systems. Multiple annotations allowed for the assessment of inter-annotator (dis)agreement, thereby allowing for an evaluation of the reference annotations used to evaluate the automatic systems. The rhythmogram has been identified in previous research as a feature capable of capturing characteristics of rhythmic content of a music recording. We present here a direct evaluation of its ability to characterise the metrical structure and as a result we propose a method to explicitly extract metrical structure descriptors from it. Despite generally good and increasing performance, such rhythm features extraction systems occasionally fail. When unpredictable, the failures are a barrier to usability and development of trust in MIR systems. In a bid to address this issue, we then propose a method to estimate the reliability of rhythm features extraction. Finally, we propose a two-fold method to automatically analyse metric modulations from audio recordings. On the one hand, we propose a method to detect metrical structure changes from the rhythmogram feature in an unsupervised fashion. On the other hand, we propose a metric modulations taxonomy rooted in music theory that relies on metrical structure descriptors that can be automatically estimated. Bringing these elements together lays the ground for the automatic production of a musicological interpretation of metric modulations.EPSRC award 1325200 and Omnifone Ltd

Generative rhythmic models

A system for generative rhythmic modeling is presented. The work aims to explore computational models of creativity, realizing them in a system designed for realtime generation of semi-improvisational music. This is envisioned as an attempt to develop musical intelligence in the context of structured improvisation, and by doing so to enable and encourage new forms of musical control and performance; the systems described in this work, already capable of realtime creation, have been designed with the explicit intention of embedding them in a variety of performance-based systems. A model of qaida, a solo tabla form, is presented, along with the results of an online survey comparing it to a professional tabla player's recording on dimensions of musicality, creativity, and novelty. The qaida model generates a bank of rhythmic variations by reordering subphrases. Selections from this bank are sequenced using a feature-based approach. An experimental extension into modeling layer- and loop-based forms of electronic music is presented, in which the initial modeling approach is generalized. Starting from a seed track, the layer-based model utilizes audio analysis techniques such as blind source separation and onset-based segmentation to generate layers which are shuffled and recombined to generate novel music in a manner analogous to the qaida model.M.S.Committee Chair: Chordia, Parag; Committee Member: Freeman, Jason; Committee Member: Weinberg, Gi

Proceedings of “The Healing and Emotional Power of Music and Dance (HELP-MD)” Symposium.

UIDB/00472/2020 UIDP/00472/2020publishersversionpublishe

Digital architecture and difference: a theory of ethical transpositions towards nomadic embodiments in digital architecture

This thesis contributes to histories and theories of digital architecture of the past two decades, as it questions the narratives of its novelty. The main argument this thesis puts forward is that a plethora of methodologies, displacing the centrality of the architect from the architectural design process, has folded into the discipline in the process of its rewriting along digital protocols. These steer architecture onto a post-human path. However, while the redefinition of the practice unfolds, it does so epistemically only without redefining the new subject of architecture emerging from these processes, which therefore remains anchored to humanist-modern definitions. This unaccounted-for position, I argue, prevents novelty from emerging. Simultaneously, the thesis unfolds a creative approach – while drawing on nomadic, critical theory concepts, there surfaces an alternative genealogy already underpinning digital methodologies that enable a reconceptualization of novelty framed with difference to be articulated through nomadic digital embodiment. Regarding the first claim, I turn to the narratives as well as to the mechanisms of digital discourse emerging in two modes of production – mathematical and biological – in exploration of the ways perceptions of novelty are articulated: a) through close readings of its narratives as they consolidate into digital architectural theory (Carpo 2011; Lynn 2003, 2012; Terzidis 2006; Migayrou 2004, 2009); b) through an analysis of the two digital methodologies that support these narratives – parametric architecture and biodigital architecture. In parallel, this thesis draws on twentieth-century critical theory and twenty-firstcentury nomadic feminist theory to rethink two thematic topics: difference and subjectivity. Specifically, these are Gilles Deleuze’s non-essentialist, nonrepresentational philosophy of difference (1968, 1980, 1988) and Rosi Braidotti’s nomadic feminist reconceptualization of post-human, nonunitary subjectivity (2006, 2011, 2015). Nomadic feminist theory also informs my methodology. I draw on Rosi Braidotti’s cartographing and transposing (2006, 2011) because they engender a non-dualist approach to research itself that is dynamic and affirmative, insisting on grounding techniques – grounding in subject positions that are nevertheless post-human and nonunitary. This leads to a redefinition of novel digital practices with ethical ones