Beat precision and perceived danceability in drum grooves

Musicians can place the time-position of events with high precision and according to personal preference, genre and tempo [1]. For instance, the swing ratio is not kept constant, but it is systematically adapted to a global tempo [2]. In contemporary music, drummers can achieve a specific feel by manipulating the timing of rhythms in different ways and placing event onsets earlier or later compared to the time reference [1]. These small adjustments in time are also referred to as micro-timing variations. The aim of this study was to investigate the influence of micro-timing variations in live-played rhythms on the perceived danceability and timing precision. The stimuli were chosen from Câmara et al. [1] where drummers were playing two different patterns with different timing styles (laid-back, pushed, on-beat). Two drummers’ performances were selected based on their reported average systematic timing. These 12 recordings were mixed with the instrumental backing track (bass and guitar) heard by the drummers to form the stimuli. Forty participants (M = 28.23 years, SD = 11.80), 28 males and 12 females, with varying musical background were recruited via social media (Facebook pages, groups and direct messages to chat groups). Participants were sent a link to the online listening test using Google Forms with modifications that presented the stimuli as embedded videos. Each video started with a prompt to wear headphones followed by 4 bars of groove for a total of 11 seconds (with a static image). For each page, the participant was presented with a reference track (on-beat timing) and a “beat” track (laid-back or pushed timing) and asked to rate the perceived danceability from 1 (not danceable at all) to 5 (very danceable). Additionally, listeners were asked to compare the beat with the reference track and indicate whether this was pushed (ahead), laid-back (behind) or on-beat (synced with) the reference in terms of timing. Preliminary results indicate that micro-timing variations affect the perceived danceability. On-beat patterns were rated with the highest danceability, followed by laid-back and pushed styles. The drummer that obtained the highest danceability rating for the laid-back performance is also the one that was mainly recognized as on-beat performer. As expected, identification of timing (ahead, behind or on) proved to be difficult. Using the instrumental backing track as a time reference could possibly have made the task even harder for untrained listeners. Future research could address this by comparing danceability ratings for the grooves mixed with different backing tracks. References [1] G. S. Câmara, K. Nymoen, O. Lartillot, and A. Danielsen, “Timing Is Everything…Or Is It? Effects of Instructed Timing Style, Reference, and Pattern on Drum Kit Sound in Groove-Based Performance,” Music Percept., vol. 38, no. 1, pp. 1–26, Sep. 2020, doi: 10.1525/mp.2020.38.1.1. [2] H. Honing and W. B. de Haas, “Swing Once More: Relating Timing and Tempo in Expert Jazz Drumming,” Music Percept., vol. 25, no. 5, pp. 471–476, Jun. 2008, doi: 10.1525/mp.2008.25.5.471

Climate changes in mangrove forests and salt marshes

This synthesis is framed within the scope of the Brazilian Benthic Coastal Habitat Monitoring Network (ReBentos WG 4: Mangroves and Salt Marshes), focusing on papers that examine biodiversity-climate interactions as well as human-induced factors including those that decrease systemic resilience. The goal is to assess difficulties related to the detection of climate and early warning signals from monitoring data. We also explored ways to circumvent some of the obstacles identified. Exposure and sensitivity of mangrove and salt marsh species and ecosystems make them extremely vulnerable to environmental impacts and potential indicators of sea level and climate-driven environmental change. However, the interpretation of shifts in mangroves and salt marsh species and systemic attributes must be scrutinized considering local and setting-level energy signature changes; including disturbance regime and local stressors, since these vary widely on a regional scale. The potential for adaptation and survival in response to climate change depends, in addition to the inherent properties of species, on contextual processes at the local, landscape, and regional levels that support resilience. Regardless of stressor type, because of the convergence of social and ecological processes, coastal zones should be targeted for anticipatory action to reduce risks and to integrate these ecosystems into adaptation strategies. Management must be grounded on proactive mitigation and collaborative action based on long-term ecosystem-based studies and well-designed monitoring programs that can 1) provide real-time early warning and 2) close the gap between simple correlations that provide weak inferences and process-based approaches that can yield increasingly reliable attribution and improved levels of anticipation.Esta é uma síntese enquadrada na Rede de Monitoramento de Habitats Bentônicos Costeiros (ReBentos, GT4: Manguezais e Marismas), embasada em literatura científica que examina interações entre clima e biodiversidade, assim como fatores antrópicos, incluindo aqueles responsáveis pela diminuição da resiliência sistêmica. O objetivo deste trabalho é determinar as dificuldades quanto à detecção de sinais precoces e alertas de mudanças climáticas com dados de monitoramento. No presente trabalho, também foram exploradas formas de contornar os diversos obstáculos identificados. A exposição e a sensitividade de espécies de mangue e de marisma, bem como dos ecossistemas dos quais fazem parte, os tornam extremamente vulneráveis e potenciais indicadores ambientais de mudanças de nível do mar e outras respostas às variações do clima. Entretanto, a interpretação de mudanças em manguezais e marismas e em seus atributos sistêmicos deve ser meticulosa, considerando assinatura energética, regime de distúrbios e pressões ambientais em cada local de estudo. Os potenciais de adaptação e de sobrevivência, em resposta a tais mudanças, dependem da fisiologia de cada espécie e dos processos contextuais onde reside a resiliência e a capacidade de persistir (em níveis local, de paisagem e regionais). A zona costeira deve ser alvo de medidas antecipatórias para redução de riscos por quaisquer impactos, uma vez que nela há intensa convergência de processos sociais e ecológicos. Os ecossistemas dessa zona devem ser integrados em estratégias de adaptação. O manejo costeiro deve ser embasado em mitigação pró-ativa e colaborativa de longo-termo, sempre com base em estudos ecossistêmicos e em programas de monitoramento que possam 1) prover sistema de alerta precoce; 2) preencher lacunas entre correlações simplistas que proveem inferências fracas, e abordagens baseadas em processos que levem a atribuições mais confiáveis e a melhores níveis de antecipação

Timing Is Everything . . . Or Is It? Investigating Timing and Sound Interactions in the Performance of Groove-Based Microrhythm

This thesis investigates the expressive means through which musicians well versed in groove-based music shape the timing of a rhythmic event, with a focus on the interaction between produced timing and sound features. In three performance experiments with guitarists, bassists, and drummers, I tested whether musicians systematically manipulate acoustic factors such as duration, intensity, and volume when they want to play with a specific microrhythmic style (pushed, on-the-beat, or laid-back). The results show that all three groups of instrumentalists indeed played pushed, on-the-beat, or laid-back relative to the reference pulse and in line with the instructed microrhythmic styles, and that there were systematic and consequential sound differences. Guitarists played backbeats with a longer duration and darker sound in relation to pushed and laid-back strokes. Bassists played pushed beats with higher intensity than on-the-beat and laid-back strokes. For the drummers, we uncovered different timing–sound combinations, including the use of longer duration (snare drum) and higher intensity (snare drum and hi-hat), to distinguish both laid-back and pushed from on-the-beat strokes. The metronome as a reference pulse led to less marked timing profiles than the use of instruments as a reference, and it led in general to earlier onset positions as well, which can perhaps be related to the phenomenon of “negative mean asynchrony.” We also conducted an in-depth study of the individual drummers’ onset and intensity profiles using hierarchical cluster analyses and phylogenetic tree visualizations and uncovered a diverse range of strategies. The results support the research hypothesis that both temporal and sound-related properties contribute to how we perceive the location of a rhythmic event in time. I discuss these results in light of theories and findings from other studies of the perception and performance of groove, as well as research into rhythm and microrhythmic phenomena such as perceptual centers and onset asynchrony/anisochrony

Groove

This chapter provides an overview of the concept of groove, investigating musical and sonic components of grooves as well as aspects related to pleasure, process, and affect. It starts out by addressing three distinct general understandings of groove: (1) pattern and performance; (2) pleasure and “wanting to move”; and (3) a state of being. The authors then propose a set of typical (rhythmic) features that seem to be common to a wide range of groove-based styles, exploring five main categories: pulse or regular beat; subdivision of the beat; syncopation; counter-rhythm; and microrhythm. Finally, the chapter presents some viable approaches to the analysis of groove, focusing on swing and anticipated beats in James Brown’s “Get Up (I Feel Like Being A) Sex Machine” (1970), aspects of counter-rhythm in Jackie Wilson’s “(Your Love Keeps Lifting Me) Higher and Higher” (1967), and the extending of beats into beat bins in D’Angelo’s “Left & Right” (2000) and Rihanna’s “Needed Me” (2016). The Oxford Handbook of Critical Concepts in Music Theory edited by Alexander Rehding and Steven Rings, 2018, reproduced by permission of Oxford University Press. DOI: 10.1093/oxfordhb/9780190454746.013.1

Timing Is Everything... Or Is It? Effects of Instructed Timing Style, Reference and Pattern on Drum Kit Sound in Groove-Based Performance

THIS STUDY REPORTS ON AN EXPERIMENT THAT tested whether drummers systematically manipulated not only onset but also duration and/or intensity of strokes in order to achieve different timing styles. Twenty-two professional drummers performed two patterns (a simple ‘‘back-beat’’ and a complex variation) on a drum kit (hi-hat, snare, kick) in three different timing styles (laid-back, pushed, on-beat), in tandem with two timing references (metronome and instrumental backing track). As expected, onset location corresponded to the instructed timing styles for all instruments. The instrumental reference led to more pronounced timing profiles than the metronome (pushed strokes earlier, laid-back strokes later). Also, overall the metronome reference led to earlier mean onsets than the instrumental reference, possibly related to the ‘‘negative mean asynchrony’’ phenomenon. Regarding sound, results revealed systematic differences across participants in the duration (snare) and intensity (snare and hi-hat) of strokes played using the different timing styles. Pattern also had an impact: drummers generally played the rhythmically more complex pattern 2 louder than the simpler pattern 1 (snare and kick). Overall, our results lend further evidence to the hypothesis that both temporal and sound-related features contribute to the indication of the timing of a rhythmic event in groove-based performance

Sound-producing actions in guitar performance of groove-based microrhythm

This paper reports on an experiment that investigated how guitarists signal the intended timing of a rhythmic event in a groove-based context via three different features related to sound-producing motions of impulsive chord strokes (striking velocity, movement duration and fretboard position). 21 expert electric guitarists were instructed to perform a simple rhythmic pattern in three different timing styles—"laidback," "on-the-beat," and "pushed"—in tandem with a metronome. Results revealed systematic differences across participants in the striking velocity and movement duration of chords in the different timing styles. In general, laid-back strokes were played with lower striking velocity and longer movement duration relative to on-the-beat and pushed strokes. No differences in the fretboard striking position were found (either closer to the "bridge" [bottom] or to the "neck" [head]). Correlations with previously-reported audio features of the guitar strokes were also investigated, where lower velocity and longer movement duration generally corresponded with longer acoustic attack duration (signal onset to offset)

Where is the beat in that note? Effects of attack, duration, and frequency on the perceived timing of musical and quasi-musical sounds

The perceptual center (P-center) of a sound is typically understood as the specific moment at which it is perceived to occur. Using matched sets of real and artificial musical sounds as stimuli, we probed the influence of attack (rise time), duration, and frequency (center frequency) on perceived P-center location and P-center variability. Two different methods to determine the P-centers were used: Clicks aligned in-phase with the target sounds via the method of adjustment, and tapping in synchrony with the target sounds. Attack and duration were the primary cues for P-center location and P-center variability; P-center variability was found to be a useful measure of P-center shape. Consistent interactions between attack and duration were also found. Probability density distributions for each stimulus display a systematic pattern of P-center shapes ranging from narrow peaks close to the onset of sounds with fast attack and short duration, to wider and flatter shapes indicating a range synchronization points for sounds with slow attack and long duration. The results support the conception of P-centers as not simple time points, but “beat bins” with characteristic shapes, and the shapes and locations of these beat bins are dependent upon both the stimulus and the synchronization task.peerReviewe

Early Evidence for Zika Virus Circulation among Aedes aegypti Mosquitoes, Rio de Janeiro, Brazil

During 2014–2016, we conducted mosquito-based Zika virus surveillance in Rio de Janeiro, Brazil. Results suggest that Zika virus was probably introduced into the area during May–November 2013 via multiple in-country sources. Furthermore, our results strengthen the hypothesis that Zika virus in the Americas originated in Brazil during October 2012–May 2013