Computational methods for percussion music analysis : the afro-uruguayan candombe drumming as a case study

Most of the research conducted on information technologies applied to music has been largely limited to a few mainstream styles of the so-called `Western' music. The resulting tools often do not generalize properly or cannot be easily extended to other music traditions. So, culture-specific approaches have been recently proposed as a way to build richer and more general computational models for music. This thesis work aims at contributing to the computer-aided study of rhythm, with the focus on percussion music and in the search of appropriate solutions from a culture specifc perspective by considering the Afro-Uruguayan candombe drumming as a case study. This is mainly motivated by its challenging rhythmic characteristics, troublesome for most of the existing analysis methods. In this way, it attempts to push ahead the boundaries of current music technologies. The thesis o ers an overview of the historical, social and cultural context in which candombe drumming is embedded, along with a description of the rhythm. One of the specific contributions of the thesis is the creation of annotated datasets of candombe drumming suitable for computational rhythm analysis. Performances were purposely recorded, and received annotations of metrical information, location of onsets, and sections. A dataset of annotated recordings for beat and downbeat tracking was publicly released, and an audio-visual dataset of performances was obtained, which serves both documentary and research purposes. Part of the dissertation focused on the discovery and analysis of rhythmic patterns from audio recordings. A representation in the form of a map of rhythmic patterns based on spectral features was devised. The type of analyses that can be conducted with the proposed methods is illustrated with some experiments. The dissertation also systematically approached (to the best of our knowledge, for the first time) the study and characterization of the micro-rhythmical properties of candombe drumming. The ndings suggest that micro-timing is a structural component of the rhythm, producing a sort of characteristic "swing". The rest of the dissertation was devoted to the automatic inference and tracking of the metric structure from audio recordings. A supervised Bayesian scheme for rhythmic pattern tracking was proposed, of which a software implementation was publicly released. The results give additional evidence of the generalizability of the Bayesian approach to complex rhythms from diferent music traditions. Finally, the downbeat detection task was formulated as a data compression problem. This resulted in a novel method that proved to be e ective for a large part of the dataset and opens up some interesting threads for future research.La mayoría de la investigación realizada en tecnologías de la información aplicadas a la música se ha limitado en gran medida a algunos estilos particulares de la así llamada música `occidental'. Las herramientas resultantes a menudo no generalizan adecuadamente o no se pueden extender fácilmente a otras tradiciones musicales. Por lo tanto, recientemente se han propuesto enfoques culturalmente específicos como forma de construir modelos computacionales más ricos y más generales. Esta tesis tiene como objetivo contribuir al estudio del ritmo asistido por computadora, desde una perspectiva cultural específica, considerando el candombe Afro-Uruguayo como caso de estudio. Esto está motivado principalmente por sus características rítmicas, problemáticas para la mayoría de los métodos de análisis existentes. Así , intenta superar los límites actuales de estas tecnologías. La tesis ofrece una visión general del contexto histórico, social y cultural en el que el candombe está integrado, junto con una descripción de su ritmo. Una de las contribuciones específicas de la tesis es la creación de conjuntos de datos adecuados para el análisis computacional del ritmo. Se llevaron adelante sesiones de grabación y se generaron anotaciones de información métrica, ubicación de eventos y secciones. Se disponibilizó públicamente un conjunto de grabaciones anotadas para el seguimiento de pulso e inicio de compás, y se generó un registro audiovisual que sirve tanto para fines documentales como de investigación. Parte de la tesis se centró en descubrir y analizar patrones rítmicos a partir de grabaciones de audio. Se diseñó una representación en forma de mapa de patrones rítmicos basada en características espectrales. El tipo de análisis que se puede realizar con los métodos propuestos se ilustra con algunos experimentos. La tesis también abordó de forma sistemática (y por primera vez) el estudio y la caracterización de las propiedades micro rítmicas del candombe. Los resultados sugieren que las micro desviaciones temporales son un componente estructural del ritmo, dando lugar a una especie de "swing" característico. El resto de la tesis se dedicó a la inferencia automática de la estructura métrica a partir de grabaciones de audio. Se propuso un esquema Bayesiano supervisado para el seguimiento de patrones rítmicos, del cual se disponibilizó públicamente una implementación de software. Los resultados dan evidencia adicional de la capacidad de generalización del enfoque Bayesiano a ritmos complejos. Por último, la detección de inicio de compás se formuló como un problema de compresión de datos. Esto resultó en un método novedoso que demostró ser efectivo para una buena parte de los datos y abre varias líneas de investigación

Tracking beats and microtiming in Afro-Latin American music using conditional random fields and deep learning

Trabajo presentado en ISMIR 2019 : 20th Conference of the International Society for Music Information Retrieval, Delft, Netherlands, 4-8 nov, 2019PostprintEvents in music frequently exhibit small-scale temporal deviations (microtiming), with respect to the underlying regular metrical grid. In some cases, as in music from the Afro-Latin American tradition, such deviations appear systematically, disclosing their structural importance in rhythmic and stylistic configuration. In this work we explore the idea of automatically and jointly tracking beats and microtiming in timekeeper instruments of Afro-Latin American music, in particular Brazilian samba and Uruguayan candombe. To that end, we propose a language model based on conditional random fields that integrates beat and onset likelihoods as observations. We derive those activations using deep neural networks and evaluate its performance on manually annotated data using a scheme adapted to this task. We assess our approach in controlled conditions suitable for these timekeeper instruments, and study the microtiming profiles’ dependency on genre and performer, illustrating promising aspects of this technique towards a more comprehensive understanding of these music traditions

CARAT : computer-aided rhythmic analysis toolbox

CARAT is a toolbox for computer-aided rhythm analysis from audio recordings that includes a set of ready-to-use tools in order to ease the adoption of computational tools by musicologists, while at the same time making readily available to MIR researchers some recently developed techniques for rhythm analysis, along with musical examples of their applicability. Pieces from three different corpora of music from the Afro-Atlantic tradition were taken as case studies for rhythmic pattern analysis

The Interpersonal Entrainment in Music Performance Data Collection

The Interpersonal Entrainment in Music Performance Data Collection (IEMPDC) comprises six related corpora of music research materials: Cuban Son & Salsa (CSS), European String Quartet (ESQ), Malian Jembe (MJ), North Indian Raga (NIR), Tunisian Stambeli (TS), and Uruguayan Candombe (UC). The core data for each corpus comprises media files and computationally extracted event onset timing data. Annotation of metrical structure and code used in the preparation of the collection is also shared. The collection is unprecedented in size and level of detail and represents a significant new resource for empirical and computational research in music. In this article we introduce the main features of the data collection and the methods used in its preparation. Details of technical validation procedures and notes on data visualization are available as Appendices. We also contextualize the collection in relation to developments in Open Science and Open Data, discussing important distinctions between the two related concepts

Multi-channel approaches for musical audio content analysis

The goal of this research project is to undertake a critical evaluation of signal representations for musical audio content analysis. In particular it will contrast three different means for undertaking the analysis of micro-rhythmic content in Afro-Latin American music, namely through the use of: i) stereo or mono mixed recordings; ii) separated sources obtained via state of the art musical audio source separation techniques; and iii) the use of perfectly separated multi-track stems. In total the project comprises the following four objectives: i) To compile a dataset of mixed and multi-channel recordings of the Brazilian Maracatu musicians; ii) To conceive methods for rhythmical micro-variations analysis and pattern recognition; iii) To explore diverse music source separation approaches that preserve micro-rhythmic content; iv) To evaluate the performance of several automatic onset estimation approaches; and v) To compare the rhythmic analysis obtained from the original multi-channel sources versus the separated ones to evaluate separation quality regarding microtiming identification

Reconocimiento de patrones rítmicos en señales de audio

En este trabajo se presenta una metodología para el reconocimiento automático de patrones rítmicos en señales de audio, usando cadenas ocultas de Markov como herramienta de clasificación. Los experimentos reportados se concentran en el ritmo del candombe, en particular en los patrones rítmicos de los tambores repique y piano. En el caso del repique, se busca identificar en el audio algunos patrones rítmicos, propuestos por Luis Jure en su trabajo “Principios generativos del toque de repique del candombe”. La implementación de la metodología utiliza audio sintético para el entrenamiento de las cadenas ocultas, y los resultados obtenidos en el reconocimiento son muy buenos si el audio que se quiere clasificar es también sintético, obteniendo más del 90 % de acierto en la clasificación. Si se usa audio sintético para entrenar y grabaciones reales para clasificar, el desempeño cae drásticamente, siendo menor a 10 % en las pruebas realizadas. Se discuten algunas alternativas para mejorar la clasificación en ese caso, una de las cuales es implementada. Aún así, la clasificación de audios reales no mejora demasiado, resultando apenas superior al 10 %. Para el tambor piano, el problema es identificar en el audio qué compases se corresponden con su patrón más típico (referido usualmente como base de piano) y cuáles no (lo que se conoce como piano repicado). En este caso, tanto el entrenamiento como la evaluación de desempeño se realizan con grabaciones reales, y en ese caso se logra un buen porcentaje en la clasificación (superior al 80 % en todas las pruebas realizadas)

The Music Sound

A guide for music: compositions, events, forms, genres, groups, history, industry, instruments, language, live music, musicians, songs, musicology, techniques, terminology , theory, music video. Music is a human activity which involves structured and audible sounds, which is used for artistic or aesthetic, entertainment, or ceremonial purposes. The traditional or classical European aspects of music often listed are those elements given primacy in European-influenced classical music: melody, harmony, rhythm, tone color/timbre, and form. A more comprehensive list is given by stating the aspects of sound: pitch, timbre, loudness, and duration. Common terms used to discuss particular pieces include melody, which is a succession of notes heard as some sort of unit; chord, which is a simultaneity of notes heard as some sort of unit; chord progression, which is a succession of chords (simultaneity succession); harmony, which is the relationship between two or more pitches; counterpoint, which is the simultaneity and organization of different melodies; and rhythm, which is the organization of the durational aspects of music