A latent rhythm complexity model for attribute-controlled drum pattern generation

AbstractMost music listeners have an intuitive understanding of the notion of rhythm complexity. Musicologists and scientists, however, have long sought objective ways to measure and model such a distinctively perceptual attribute of music. Whereas previous research has mainly focused on monophonic patterns, this article presents a novel perceptually-informed rhythm complexity measure specifically designed for polyphonic rhythms, i.e., patterns in which multiple simultaneous voices cooperate toward creating a coherent musical phrase. We focus on drum rhythms relating to the Western musical tradition and validate the proposed measure through a perceptual test where users were asked to rate the complexity of real-life drumming performances. Hence, we propose a latent vector model for rhythm complexity based on a recurrent variational autoencoder tasked with learning the complexity of input samples and embedding it along one latent dimension. Aided by an auxiliary adversarial loss term promoting disentanglement, this effectively regularizes the latent space, thus enabling explicit control over the complexity of newly generated patterns. Trained on a large corpus of MIDI files of polyphonic drum recordings, the proposed method proved capable of generating coherent and realistic samples at the desired complexity value. In our experiments, output and target complexities show a high correlation, and the latent space appears interpretable and continuously navigable. On the one hand, this model can readily contribute to a wide range of creative applications, including, for instance, assisted music composition and automatic music generation. On the other hand, it brings us one step closer toward achieving the ambitious goal of equipping machines with a human-like understanding of perceptual features of music

Intelligent Tools for Drum Loop Retrieval and Generation

Large libraries of musical data are an increasingly common feature of contemporary computer-based music production practice, with producers often relying heavily on large, curated libraries of data such as loops and samples when making tracks. Drum loop libraries are a particularly common type of library in this context. However, their typically large size, coupled with often poor user interfaces means navigating and exploring them in a fast, easy and enjoyable way is not always possible. Additionally, writing a drum part for a whole track out of many drum loops can be a laborious process, requiring manually editing of many drum loops. The aim of this thesis is to contribute novel techniques based on Music Information Retrieval (MIR) and machine learning that make the process of writing drum tracks using drum loops faster, easier and more enjoyable. We primarily focus on tools for drum loop library navigation and exploration, with additional work on assistive generation of drum loops. We contribute proof-of-concept and prototype tools, Groove Explorer and Groove Explorer 2, for drum loop library exploration based on an interface applying similarity-based visual arrangement of drum loops. Work on Groove Explorer suggested that there were limitations in the existing state-of-the-art approaches to drum loop similarity modelling that must be addressed for tools such as ours to be successful. This was verified via a perceptual study, which identified possible areas of improvement in similarity modelling. Following this, we develop and evaluate a set of novel models for drum loop analysis that capture rhythmic structure and the perceptually relevant qualities of microtiming. Drawing from this, a new approach to drum loop similarity modelling was verified in context as part of Groove Explorer 2, which we evaluated via a user study. The results indicated that our approach could make drum loop library exploration faster, easier and more enjoyable. We finally present an automatic drum loop generation system, jaki, that uses a novel approach for drum loop generation according to user constraints, that could extend Groove Explorer 2 as a drum loop editing and composition tool. Combined, these two systems could offer an end-to-end solution to improved writing of drum tracks

Growing music from seeds : parametric generation and control of seed-based msuic for interactive composition and performance

Thesis (M.S.)--Massachusetts Institute of Technology, Program in Media Arts & Sciences, 1994.Includes bibliographical references (p. 78-79).by Alexander Rigopulos.M.S

Live Interface for Generative Rhythm Sequencing

As técnicas de sequenciação ritmica tradicionais nem sempre proporcionam o ambiente ideal para programar padrões complexos e em constante mutação pela natureza linear do seu controlo. As técnicas disponiveis para a geração de variações de um ritmo programado são vulgarmente sustentadas em simples processos de aleatoriedade ou requerem um processo complexo de programação ritmica que não joga a favor do sequenciador enquanto instrumento performativo do ponto de vista do músico. Assim, surge a ideia de criar um sistema interactivo capaz de gerar variações ritmicamente informadas de uma sequência criada pelo utilizador, através de descritores siginificativos que possibilitam um controlo performativo, de forma directa e familiar, em tempo real, da sequenciação ritmica. Para o efeito, foi utilizado o Rhythmicator, uma aplicação feita em Max/MSP que faz geração automática de ritmos em tempo real consoante um determinado compasso, fazendoa ponte entre a sequência escrita pelo utilizador e o processo generativo. O desenvolvimento do sistema foi feito no ambiente de programação Pure Data, tendo algumas partes do código de Max/MSP do Rhythmicator sido traduzidas para o projecto. Um controlador MIDI é utilizado para interagir com o patch de Pure Data do sistema que, por sua vez, envia mensagens MIDI para qualquer instrumento que o aceite.Keywords: ritmo generativo, sequenciação performativa, tempo real, rhythmicator, pure data,modelo estocástico, barlow, indispensabilidade métrica, controlo físicoTraditional rhythmic sequencing techniques are often not ideal to program complex evolving patterns as they offer only linear control to the player. Techniques available to generate variations of a programmed rhythm usually rely on simple randomness or complex programming actions that do not favor the sequencer as a live playing instrument from the musician's perspective. With this in mind, our idea was to create an interactive system able to generate rhythmically informed variations of a pattern previously entered by the user in a direct and familiar real time performative manner, by means of meaningful generative descriptors providing nuanced control over the complex rhythmic sequencing. To this end, Rhythmicator, a Max/MSP application that automatically generates rhythms in real time in a given meter was used to tackle the generative process around the sequence written by the user. The development of the system is based on the Pure Data programmingenvironment, having some parts of Rhythmicator's Max/MSP code been translated and used for this project. A MIDI controller is used to interact with the system's Pure Data patch and MIDI triggers are sent to any MIDI-able device intended.Keywords: generative rhythm, performative sequencing, real time, rhythmicator, pure data, stochasticmodel, barlow, metric indispensability, physical contro

Developing a Polyrhythmic Idiolect

This practice-based multi-media study sets out to reveal how procedural methodologies effect transformative change in a polyrhythmic drum-set idiolect, premised on the idea that archetypal variants and phraseological patterning constituting my musical “voice” are, primarily, results of a procedural mind rather than aggregations of replicative ideas acquired from elsewhere. The thesis accordingly sets out a detailed participant-observer study designed to reveal methodological processes and outcomes pertaining to the cultivation of a unique sonic identity. In revealing how structural-organisational processes can evolve personalised ways of manipulating rhythm, this research offers new analytical tools for understanding what improvising drummers do. Two important aims of the study are (a) to effect and document transformative change in my drum-set language through the application of improvisational methodologies, and (b) to reveal these procedures in operation from a participant-observer perspective, thereby showing how sonic identity can be individuated through personal agency and decision-making/selection processes operating within constraints. Original generative methodologies for hybridizing vocabulary and propagating unique archetypal variants – namely, the Iterative Loop Cycle and Transitional Synthesis - are central to this project, which targets six developmental areas: Suspended Primary Pulsation, Densities, Pulse Streaming, Transposing Rhythm, Isochronous Asymmetry and Mixed Rates

Efficacy of Rhythmic Acquisition on Gait Performance Among Individuals with Parkinson’s Disease

The purpose of this study was to identify the ability of individuals with Parkinson’s disease (PD) to acquire different rhythmic complexity levels through individual home-based Improvised Active Music Therapy (IAMT) sessions. The study aimed to identify whether higher acquisition of rhythmic complexity levels improved gait performance, as well as beat perception and production abilities. In this single subject multiple baseline design, the study measured the ability of four right-handed participants with PD to acquire greater density of syncopation, as a measure of rhythmic complexity levels, while playing uninterrupted improvised music on a simplified electronic drum-set. An accredited music therapist led each session with an acoustic guitar. The study described how higher density of syncopation levels presented in participants’ playing related to not only gait performance, and beat perception and production abilities, but also to other music measurements. The participants’ music content was transformed into digital music data in real time using Musical Instrument Digital Interface (MIDI). MIDI data was analyzed to determine density of syncopation, note count, velocity, and asynchrony during baseline and treatment IAMT intervention. Results from visual analyses and Pearson correlations indicated partial evidence for the ability of individuals with PD to acquire different rhythmic complexity levels through IAMT. Partial evidence was also found to support the overall effectiveness of IAMT sessions in increasing participant’s mean gait velocity and stride length, and reducing step time and stride length variability. The findings of the current study indicate that IAMT sessions could be an effective strategy to increase physical mobility among individuals with PD. Using MIDI in the IAMT approach can yield data to evaluate treatment effectiveness and assess patient progress, providing daily measures and analysis of data using statistical analyses alongside visual analysis. This method has the potential to lead to new evidence-based interventions modeled in music therapy

A Practice-Based Study into the Composition and Performance of Polytemporal Music

This practice-based research explores the composition and performance of polytemporal music, culminating in ten new works in audio/visual format with accompanying commentaries and notation. Research is undertaken into concepts of rhythm and pulse in order to develop new techniques for composing music in multiple simultaneous tempi, particularly methods for managing rhythmic consonance and dissonance in the compositional process. Attention is also given to the practicalities and implications of performance, investigating issues of accessibility and ensemble in reference to the use of click tracks and headphones, as well as the form and function of notation. The approaches within this research stem from my experience as a commercial rock/studio musician fused with contemporary classical influences. As well as these musical influences, a background in visual art and design also contributes to the visual presentation of works and scores; musical works are presented in video format which is shown to enhance temporal perception, and a new form of rhythmically accurate western notation for polytemporal music is developed. Composing and performing in a strictly polytemporal setting has at the time of writing not been widely researched, and it is hoped this work displays new knowledge and approaches important for the development of composition in this area

Interactive real-time musical systems

PhDThis thesis focuses on the development of automatic accompaniment systems. We investigate previous systems and look at a range of approaches that have been attempted for the problem of beat tracking. Most beat trackers are intended for the purposes of music information retrieval where a `black box' approach is tested on a wide variety of music genres. We highlight some of the diffculties facing offline beat trackers and design a new approach for the problem of real-time drum tracking, developing a system, B-Keeper, which makes reasonable assumptions on the nature of the signal and is provided with useful prior knowledge. Having developed the system with offline studio recordings, we look to test the system with human players. Existing offline evaluation methods seem less suitable for a performance system, since we also wish to evaluate the interaction between musician and machine. Although statistical data may reveal quantifiable measurements of the system's predictions and behaviour, we also want to test how well it functions within the context of a live performance. To do so, we devise an evaluation strategy to contrast a machine-controlled accompaniment with one controlled by a human. We also present recent work on a real-time multiple pitch tracking, which is then extended to provide automatic accompaniment for harmonic instruments such as guitar. By aligning salient notes in the output from a dual pitch tracking process, we make changes to the tempo of the accompaniment in order to align it with a live stream. By demonstrating the system's ability to align offline tracks, we can show that under restricted initial conditions, the algorithm works well as an alignment tool