MOVING IN TIME: COMPUTATIONAL ANALYSIS OF MICROTIMING IN MARACATU DE BAQUE SOLTO Matthew E. P. Davies 1;4 Magdalena Fuentes2 João Fonseca3 Luís Aly3;4 Marco Jerónimo3 Filippo Bonini Baraldi5;6 1 University of Coimbra, CISUC, DEI, Portugal 2 CUSP, MARL, New York University, USA 3 University of Porto, Faculty of Engineering, Portugal 4 INESC TEC, Portugal 5 Ethnomusicology Institute (INET-md), FCSH, Universidade Nova de Lisboa, Portugal 6 Centre de Recherche en Ethnomusicologie (CREM-LESC), Paris Nanterre University, France [email protected] ABSTRACT “Maracatu de baque solto” is a Carnival performance com- bining music, poetry, and dance, occurring in the Zona da Mata Norte region of Pernambuco (Northeast Brazil). Maracatu percussive music is strongly repetitive, and is played as loud and as fast as possible. Both from an MIR and ethnomusicological perspective this makes a complex musical scene to analyse and interpret. In this paper we focus on the extraction of microtiming profiles towards the longer term goal of understanding how rhythmic perfor- mance in Maracatu is used to promote health and well- being. To conduct this analysis we use a set of recordings Figure 1: Maracatu de baque solto “Leão de Ouro de Con- acquired with contact microphones which minimise the in- dado” during a Carnival parade in Tupaoca (Pernambuco), terference between performers. Our analysis reveals that Feb. 28th, 2017. Photo credit: Filippo Bonini Baraldi. the microtiming profiles differ substantially from those ob- served in more widely studied South American music. In their time and money to participate in the Carnival “des- particular, we highlight the presence of dynamic microtim- file” (parade), taking place every year in Recife, the state ing profiles as well as the importance of the choice of time- capital. More than 100 groups of Maracatu de baque solto, keeper instrument, which dictates how the performances of different sizes (ranging from 15-20 members up to 200 can be understood. Throughout this work, we emphasize members) are currently active, each with their own head- the importance of a multidisciplinary approach in which quarters (“sede”) which are generally linked to individual MIR, audio engineering, and ethnomusicology must inter- families. A Maracatu performance is shown in Fig. 1. act to provide meaningful insight about this music. Maracatu de baque solto differs from another Carnival performance with a similar name, Maracatu “de baque vi- 1. INTRODUCTION rado,” not only in terms of its musical and choreographic “Maracatu de baque solto”, also known as “Maracatu ru- features, but also because it has remained a very local cul- ral”, is a Carnival performance combining music, poetry, tural practice. Indeed, while Maracatu de baque virado, and dance, occurring in the Zona da Mata Norte region of like other music from Pernambuco (e.g., forró, coco de Pernambuco (Northeast Brazil). Most inhabitants of this roda, ciranda), has recently spread out nationally and in- region, dominated by the sugar cane monoculture, are ru- ternationally, Maracatu de baque solto (hereafter shortened ral workers with very modest income, who invest most of to Maracatu) is only performed within a radius of about 100 km2 and is strongly linked to the local afro-indigenous spiritual and religious practices, specifically, the jurema- c M. E. P. Davies, M. Fuentes, J. Fonseca, L. Aly, M. umbanda worship [1]. This local dimension explains why, Jerónimo, and F. Bonini Baraldi. Licensed under a Creative Commons barring a few exceptions, it remains a largely understud- Attribution 4.0 International License (CC BY 4.0). Attribution: M. E. ied cultural expression. To the best of our knowledge no P. Davies, M. Fuentes, J. Fonseca, L. Aly, M. Jerónimo, and F. Bonini Baraldi, “Moving in Time: Computational Analysis of Microtiming in in-depth analysis of its music has ever been realised. Maracatu de Baque Solto”, in Proc. of the 21st Int. Society for Music Previous field research conducted in Condado, a small Information Retrieval Conf., Montréal, Canada, 2020. city located in the Zona da Mata Norte region, suggests that 795 Proceedings of the 21st ISMIR Conference, Montreal,´ Canada, October 11-16, 2020 the protective function of Maracatu is locally expressed and “between-instrument” microtiming, where a “time- by two key concepts: “consonância” (consonance) and keeping” instrument provides the beat reference. Our main “fechar” (closure) [2, 3]. Consonance points to a particu- findings demonstrate that the choice of the time-keeper is lar way of behaving, of dancing together, and of producing critical and can change the interpretation of the perfor- sounds. It is associated with an idea of high interpersonal mance. Furthermore, we observe microtiming profiles that coordination, as opposed to the idea of “desmantelo” (frac- change dynamically within given pieces of music, and be- ture and breaking up). The expression “fechar o Maracatu” tween pieces of music. Thus, the notion of a single charac- (closing the Maracatu) refers to various aesthetic strategies teristic microtiming profile appears not to apply to the set used to protect the individual and the community from the of Maracatu recordings under investigation here. threats that are at stake during Carnival. The percussive The remainder of this paper is structured as follows. nucleus of Maracatu plays as fast and loud as possible, sat- Section 2 provides an overview of the musical structure urating the acoustical space and “filling” each metrical po- and instruments of Maracatu. Section 3 describes the sig- sition in order to avoid any silence. To this end, the study nal acquisition process. Section 4 summarizes the micro- of systematic microtiming, i.e., intentional deviations from timing modelling approach, with our main findings pre- strict metronomic timing, can be a promising first step to- sented in Section 5. We conclude the paper in Section 6 wards understanding Maracatu performances. with a reflection on the broader impact of the research. In December 2019, 13 members of a Maracatu group “Leão de Ouro de Condado” were invited to Lisbon. Sev- 2. MARACATU DE BAQUE SOLTO eral public performances were organised which culminated in a two-part event: a parade in which musicians and Maracatu is a combination of various elements: two to dancers moved through the streets, followed by a fixed lo- four wind instruments (trumpet and trombone), played by cation, outdoor performance. We focus on the recordings “musicos” (musicians), and a nucleus of five percussionists obtained from the latter, and perform an exploratory analy- called the “terno.” During performances, the musicos and sis of the microtiming in the percussionists’ performances. terno act in close cooperation with a poet (the “mestre de apito”). When the poet improvises short verses about 30 s Our research is part of the emerging topic of compu- in duration, the musicians remain silent and the dancers tational ethnomusicology [4, 5], and falls within a grow- and public remain still. When the poet finishes his verses ing body of work examining the role of microtiming and and blows his whistle (“apito”), the percussionists and the rhythmic structure and its relationship to groove and mu- wind musicians play for about the same duration and ev- sical embodiment [6–10]. It also intersects with the ex- erybody dances. During this time, the poet prepares his isting MIR literature on the analysis of rhythm in South next verses. This alternating pattern remains throughout American music [11–16]. In our specific context, we face the performance, which may last up to eight hours. two prominent, interconnected challenges. In the absence Maracatu percussive music is highly repetitive, and of formal theories about Maracatu, there is little basis on played as loud and as fast as possible. These features give which to pose research questions that computational anal- rise to a very strong euphoria in the dancers and the pub- ysis (e.g., using MIR techniques) could address. From a lic. Just a few rhythmical patterns exist in Maracatu and more practical perspective, the very nature of Maracatu depend on the metrical form that the poet is following: performance: musicians in tight proximity to one another, the main genres are “marcha” and “samba,” although the playing very loudly, and moving between multiple ad- samba of Maracatu has nothing to do with the well-known hoc external locations, creates technical difficulties for the samba music of Brazil. In Maracatu, marcha and samba in- high-quality signal acquisition necessary for temporally- dicate both the metrical subdivision of the poet’s couplets, precise analysis of musical timing. the rhythm played by the terno, and the melodies played Our methodology to address these challenges is to con- by the musicos. Various melodies may be associated to duct the research from a strongly multidisciplinary per- the marcha pattern and/or samba pattern, depending on the spective. We directly leverage technical expertise in audio melodic line that the poet chooses to sing his verses. engineering for signal acquisition, music signal process- In Maracatu, the five percussion instruments of the ing and machine learning for computational rhythm analy- terno, shown in Fig. 2, are: Bombo – a bass drum-like in- sis, and ethnomusicology to guide the interpretation of the strument played with two sticks, one for each side. We findings based on long-term field research. By necessity, refer to Bombo High as the upper skin, and Bombo Low this leads to an exploratory approach concerning the pres- as the lower. Gonguê – an iron instrument comprised of ence and use of microtiming in Maracatu, where the com- two bells of different pitches. We refer to Gonguê High putational analysis can be used as a means to infer new as the higher, and Gonguê Low as the lower pitched bell. understanding about the musical practice. Porca – a friction drum, played with a damp cloth holding To enable the isolated analysis of the microtiming of the stick.