Guilherme Schmidt Câmara

• Anne Danielsen, Justin London, Martin Torvik Langerød & Guilherme Schmidt Câmara (2026). All About That Bass Drum? Asynchrony Effects on the Perceived Timing of Compound Musical Sounds. Annals of the New York Academy of Sciences. ISSN 0077-8923. 1560(1). doi: 10.1111/nyas.70306. Full text in Research Archive Show summary

  When a sound occurs (i.e., its acoustic onset) is not the same as when we perceive that sound to occur. The latter location is known as the “P‐center” in both music and language perception, and can be a few to over a hundred milliseconds after a sound's acoustic onset. While P‐center perception in music has received scrutiny, it remains unclear how P‐centers emerge when multiple instruments play together, particularly when they are not perfectly synchronized. Here, we investigate the effect of different degrees of instrument asynchrony on the P‐center of their combined sound. In two experiments, participants aligned a click probe to pairs of instruments used in popular music with varying asynchronies (0–±80 ms). Results show that increasing asynchrony shifts the P‐center of the compound sound later in time. Moreover, fast‐attack instruments (e.g., kick drum) exert a strong pull on the P‐center; fast–slow pairs largely retained a single P‐center anchored to the fast‐attack sound. By contrast, pairs of fast‐attack sounds with ≥40 ms asynchronies between their individual P‐centers provided evidence of perceptual segregation of the sound into two events. The findings show how inter‐instrument asynchronies and attack characteristics jointly structure the perceived timing and unity of compound musical sounds.

• Guilherme Schmidt Câmara, Connor Spiech, Sandra Solli, Birger Bang, Olga Rogulina & Bruno Laeng [Show all 7 contributors for this article] (2026). Just noticeable difference thresholds of asynchrony and non-isochrony in a Multi-Instrumental groove-based context. Journal of the Acoustical Society of America. ISSN 0001-4966. 159(5), p. 4668–4688. doi: 10.1121/10.0043887. Full text in Research Archive
• Connor Spiech, Guilherme Schmidt Câmara, Julian Fuhrer & Penhune, Virginia (2025). 4/4 and more, rhythmic complexity more strongly predicts groove in common meters. Communications Psychology. 3. doi: 10.1038/s44271-025-00360-0. Full text in Research Archive Show summary

  The pleasurable urge to move to music, termed “groove,” is thought to arise from the tension between top-down metric expectations or predictions and rhythmic complexity. Specifically, groove ratings are highest for moderately complex rhythms, balancing expectation and surprise. To test this, meter and rhythmic complexity need to be manipulated independently to assess their impact on groove. Thus, we compared Western listeners’ ratings for musical clips of varying rhythmic complexity composed in either the most common Western meter (4/4) or less common meters (e.g., 7/8). In several behavioral studies (Experiment 1, N = 143; Experiment 2, N = 120; Experiment 3, N = 120), we used Bayesian regression to show that groove is greatest for moderately complex rhythms, but only in 4/4. In non-4/4 meters, simpler rhythms elicited the greatest groove. This provides support for the theory that bottom-up rhythmic features interact with meter in a way that shapes the pleasurable urge to move to music.

• Anne Danielsen, Ragnhild Brøvig, Kjetil Klette Bøhler, Guilherme Schmidt Câmara, Mari Romarheim Haugen & Eirik Jacobsen [Show all 13 contributors for this article] (2024). There’s More to Timing than Time: Investigating Musical Microrhythm Across Disciplines and Cultures. Music Perception. ISSN 0730-7829. 41(3), p. 176–198. doi: 10.1525/mp.2024.41.3.176. Full text in Research Archive Show summary

  The TIME project: Timing and Sound in Musical Microrhythm (2017–2022) studied microrhythm; that is, how dynamic envelope, timbre, and center frequency, as well as the microtiming of a variety of sounds, affect their perceived rhythmic properties. The project involved theoretical work regarding the basic aspects of microrhythm; experimental studies of microrhythm perception, exploring both stimulus features and the participants’ enculturated expertise; observational studies of how musicians produce particular microrhythms; and ethnographic studies of musicians’ descriptions of microrhythm. Collectively, we show that: (a) altering the microstructure of a sound (“what” the sound is) changes its perceived temporal location (“when” it occurs), (b) there are systematic effects of core acoustic factors (duration, attack) on microrhythmic perception, (c) microrhythmic features in longer and more complex sounds can give rise to different perceptions of the same sound, and (d) musicians are highly aware of microrhythms and have developed vocabularies for describing them. In addition, our results shed light on conflicting results regarding the effect of microtiming on the “grooviness” of a rhythm. Our use of multiple, interdisciplinary methodologies enabled us to uncover the complexity of microrhythm perception and production in both laboratory and real-world musical contexts.

• Guilherme Schmidt Câmara, George Sioros, Kristian Nymoen, Mari Romarheim Haugen & Anne Danielsen (2023). Sound-producing actions in guitar performance of groove-based microrhythm. Empirical Musicology Review. 18(1), p. 21–36. doi: 10.18061/emr.v18i1.9124. Full text in Research Archive Show summary

  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 (neither 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).

• Mari Romarheim Haugen, Guilherme Schmidt Câmara, Kristian Nymoen & Anne Danielsen (2023). Instructed timing and body posture in guitar and bass playing in groove performance. Musicae Scientiae. ISSN 1029-8649. doi: 10.1177/10298649231182039. Full text in Research Archive Show summary

  Body movements play a crucial role in music performance and perception, and they do so well beyond those devoted to sound production itself. Various movements related to the performer’s emotional intentions or structural aspects of the music are also part of the performance and crucial to the listening experience. In the present study, we investigated the effect of instructed timing on such non-sound producing body movements, focusing on musicians’ body posture. We used an infrared motion-capture system to record the movements of skilled guitarists and bassists while they were playing electric guitar and electric bass, respectively. We instructed the musicians to perform under three different timing-style conditions: laid-back (behind), on-the-beat, and pushed (ahead). We also conducted short semistructured interviews to gain further insight into their movement strategies. The results show that performers generally leaned forward when instructed to play systematically slightly ahead of the pulse. We suggest that this change is related to an alteration in the performer’s experience of the feel of the music. The results support the view that musicians’ non-sound-producing body movements are not random, but integral to the performance, and that they are closely related to the music’s microrhythmic feel.

• Guilherme Schmidt Câmara, George Sioros & Anne Danielsen (2022). Mapping timing and intensity strategies in drum-kit performance of a simple back-beat pattern. Journal of New Music Research. ISSN 0929-8215. doi: 10.1080/09298215.2022.2150649. Full text in Research Archive Show summary

  In this article, we explore the various ways in which drummers express a simple ‘backbeat’ pattern when asked to play with different timing styles (laid-back, on-beat, pushed) via manipulation of stroke onset and intensity features. Based on hierarchical clustering analyses and phylogenetic tree visualizations, we found three main strategies used to distinguish pushed/laid-back from on-the-beat performances: (1) strong ‘general earliness/lateness’ strategies, where most instruments are consistently played earlier/later in time relative to a metrical grid; (2) subtler ‘early/late flam’ strategies, where most instruments are played synchronously with the grid but at least one instrument is distinctively played as an early/late flam ; and (3) even subtler ‘ambiguously early/late compound sound’ strategies, where two instruments form a compound sound, but one is played synchronously with the grid, while the other is played early/late. The majority of drummers used additional consistent intensity strategies, the most common being greater hi-hat or snare intensity, which might enhance the effect of laidback and pushed rhythmic events. However, intensity was not used uniformly to exclusively distinguish laid-back/pushed from on-beat timing.

• Olivier Lartillot, Kristian Nymoen, Guilherme Schmidt Câmara & Anne Danielsen (2021). Computational localization of attack regions through a direct observation of the audio waveform. Journal of the Acoustical Society of America. ISSN 0001-4966. 149(1), p. 723–736. doi: 10.1121/10.0003374. Full text in Research Archive Show summary

  This article addresses the computational estimation of attack regions in audio recordings. Previous attempts to do so were based on the reduction of the audio waveform into an envelope curve, which decreases its temporal resolution. The proposed approach detects the attack region directly from the audio waveform. The attack region is modeled as a line starting from a low-amplitude point and intersecting one of the local maxima according to two principles: (1) maximizing the slope, while favoring, at the same time, a higher peak if the slope remains only slightly lower and (2) dismissing initial attack regions of relatively low amplitude. The attack start position is fine-tuned by intersecting the attack slope with the audio waveform. The proposed method precisely pinpoints the attack region in cases where it is unambiguously observable from the waveform itself. In such cases, previous methods selected a broader attack region due to the loss of temporal resolution. When attack regions are less evident, the proposed method’s estimation remains within the range of results provided by other methods. Applied to the prediction of judgments of P-center localization [Danielsen, Nymoen, Anderson, C^amara, Langerød, Thompson, and London, J. Exp. Psychol. Hum. Percept. Perform. 45, 402–418 (2019)], the proposed method shows a significant increase in precision, at the expense of recall.

• Guilherme Schmidt Câmara, Kristian Nymoen, Olivier Lartillot & Anne Danielsen (2020). Effects of instructed timing on electric guitar and bass sound in groove performance. Journal of the Acoustical Society of America. ISSN 0001-4966. 147(2), p. 1028–1041. doi: 10.1121/10.0000724. Full text in Research Archive Show summary

  This paper reports on two experiments that investigated the expressive means through which musicians well versed in groove-based music signal the intended timing of a rhythmic event. Data were collected from 21 expert electric guitarists and 21 bassists, who were instructed to perform a simple rhythmic pattern in three different timing styles—“laidback,” “on-the-beat,” and “pushed”—in tandem with a metronome. As expected, onset and peak timing locations corresponded to the instructed timing styles for both instruments. Regarding sound, results for guitarists revealed systematic differences across participants in the duration and brightness [spectral centroid (SC)] of the guitar strokes played using these different timing styles. In general, laid-back strokes were played with a longer duration and a lower SC relative to on-the-beat and pushed strokes. Results for the bassists indicated systematic differences in intensity (sound-pressure level): pushed strokes were played with higher intensity than on-the-beat and laid-back strokes. These results lend further credence to the hypothesis that both temporal and sound-related features are important indications of the intended timing of a rhythmic event, and together these features offer deeper insight into the ways in which musicians communicate at the microrhythmic level in groove-based music.

• Guilherme Schmidt Câmara, Kristian Nymoen, Olivier Lartillot & Anne Danielsen (2020). Timing Is Everything... Or Is It? Effects of Instructed Timing Style, Reference and Pattern on Drum Kit Sound in Groove-Based Performance. Music Perception. ISSN 0730-7829. 38(1), p. 1–26. doi: 10.1525/mp.2020.38.1.1. Full text in Research Archive Show summary

  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.

• Olivier Senn, Toni Amadeus Bechtold, Dawn Rose, Guilherme Schmidt Câmara, Nina Du Vel & Rafael Jerjen [Show all 10 contributors for this article] (2020). Experience of Groove Questionnaire: Instrument Development and Initial Validation. Music Perception. ISSN 0730-7829. 38(1), p. 46–65. doi: 10.1525/MP.2020.38.1.46. Full text in Research Archive Show summary

  MUSIC OFTEN TRIGGERS A PLEASURABLE URGE IN listeners to move their bodies in response to the rhythm. In music psychology, this experience is commonly referred to as groove. This study presents the Experience of Groove Questionnaire, a newly developed self-report questionnaire that enables respondents to subjectively assess how strongly they feel an urge to move and pleasure while listening to music. The development of the questionnaire was carried out in several stages: candidate questionnaire items were generated on the basis of the groove literature, and their suitability was judged by fifteen groove and rhythm research experts. Two listening experiments were carried out in order to reduce the number of items, to validate the instrument, and to estimate its reliability. The final questionnaire consists of two scales with three items each that reliably measure respondents' urge to move (Cronbach's ¼ :92) and their experience of pleasure (¼ :97) while listening to music. The two scales are highly correlated (r ¼ :80), which indicates a strong association between motor and emotional responses to music. The scales of the Experience of Groove Questionnaire can independently be applied in groove research and in a variety of other research contexts in which listeners' subjective experience of music-induced movement and enjoyment need to be addressed: for example the study of the interaction between music and motivation in sports and research on therapeutic applications of music in people with neurological movement disorders.

• Anne Danielsen, Kristian Nymoen, Evan Anderson, Guilherme Schmidt Câmara, Martin Torvik Langerød & Marc R. Thompson [Show all 7 contributors for this article] (2019). Where is the beat in that note? Effects of attack, duration, and frequency on the perceived timing of musical and quasi-musical sounds. Journal of Experimental Psychology: Human Perception and Performance. ISSN 0096-1523. 45(3), p. 402–418. doi: 10.1037/xhp0000611. Full text in Research Archive Show summary

  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.

• George Sioros, Guilherme Schmidt Câmara & Anne Danielsen (2019). Mapping Timing Strategies in Drum Performance. In Arthur Flexer, Geoffroy Peeters, Julián Urbano & Anja Volk (Ed.), Proceedings of the 20th International Society for Music Information Retrieval Conference, ISMIR 2019. International Society for Music Information Retrieval. ISSN 9781732729919. Full text in Research Archive
• Guilherme Schmidt Câmara & Anne Danielsen (2018). Groove. In Rehding Alexander & Rings Steven (Ed.), The Oxford Handbook of Critical Concepts in Music Theory. Oxford University Press. ISSN 9780190454746. doi: 10.1093/oxfordhb/9780190454746.013.17. Full text in Research Archive Show summary

  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).

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• Guilherme Schmidt Câmara (2025). Just Noticeable Difference Thresholds of Musical Microrhythm (Asynchrony and Non-isochrony) in Multi-Instrumental Groove-based Performance. Full text in Research Archive Show summary

  Musicians can convey different ’timing feels’ in performance by manipulating asynchronies between instrument onsets (’behind’/’ahead’/’on-beat’) as well as the degree of non-isochrony within metrical subdivisions (’straight’/’swung’). The extent to which we can perceive such microtiming nuances has only yet been examined in non-/quasirhythmic contexts involving monotonic and single-layered stimuli, with mixed results regarding effect of musicianship. Studies have also found that pupil size increases linearly with asynchrony magnitude, but not yet examined non-isochrony. We measured the just noticeable difference (JND) thresholds of asynchrony (Exp. 1) and non-isochrony (Exp. 2) in a naturalistic, multi-layered groove (funk pattern, IOI 143ms) with 5 instruments (guitar/bass/kick/snare/hi-hat). Using a 1IFC staircase and global displacements of individual instrument layers (asynchrony: 1-100ms [early/late], non-isochrony: +1-71.5ms [late]), we tasked participants (N=64; musicians N=32; non-musicians N=32) to determine whether instruments were playing; "together" with or "before/after" other instruments (Exp. 1); and with "straight/even" or "swung/uneven" rhythm (Exp. 2). Pupil response was also measured. As expected, JND thresholds were higher than reported in previous literature (+4%/+2% of IOI for asynchrony and non-isochrony, respectively) likely due to greater attentional ’noise’ from additional simultaneously playing instruments, and lower for for musicians (14%/16%) than for non-musicians (22%/24%) due to greater training in the perception/ production of musical microrhythm. For the first time, we also demonstrate an effect of both Instrument and Timing displacement, where onset displacements were harder to detect: in string (22%/24%) rather than drum (15%/18%) instruments - likely due to perceptually ’fuzzier’ acoustic attack profiles; and in late (20%) rather than early (16%) displacements - likely due to forward acoustic masking effects. We also found a linear relationship between pupil size and both asynchrony and non-isochrony, further indicating that the pupil indexes mental effort in auditory processing of microrhythm more generally.

• Guilherme Schmidt Câmara (2024). Looking for the perfect JND: In search of more ecological thresholds for the perception of microrhytm in groove-based music. Full text in Research Archive Show summary

  There is currently a gap in microrhythm research regarding to what extent we perceive nuances in the timing of complex acoustic stimuli in realistic musical contexts. Classic studies tend to investigate the so-called just-noticeable difference (JND) thresholds of timing discrimination in non- or quasi-rhythmic contexts, and generally use non-musical sound stimuli such as clicks or sine waves. Findings from these studies show that we can discriminate minute timing irregularities between such simple sounds with a high degree of precision – as low as 2 milliseconds for onset asynchronies between tones (Hirsh 1959, Zera & Green 1993). In more recent decades, studies have incorporated musical sounds into discrimination experiments, though these are often still synthesized, and at best tend to resemble quasimusical/rhythmic contexts. Even so, these have revealed similar impressive acuity results, as well as further revealing important effects of tempo (IOI) and degree of musical training on timing JNDs (Frane & Shams 2017; Friberg & Sundberg 1995). To our knowledge, however, none have yet focused attention towards JND thresholds in more realistic musical contexts. As such, the extent to which results derived from non- or quasi-musical experimental settings translate to our perception of microrhythmic nuances in real groove-based music – that is, highly multilayered ensembles featuring a range of complex instrumental sounds and rhythmic patterns – remains somewhat poorly understood. In this talk, I will present an overview of some of the abovementioned salient literature on perceptual thresholds of microtiming, with focus on asynchrony (beat delay/anticipation) and anisochrony (swing). In addition, I will present some preliminary results from our own ongoing series of JND experiments which seek to generate more ecologically valid perceptual heuristics for microrhythm in simple, yet realistic, groove-based musical contexts. Results from pilot experiments on a standard funk pattern (modelled on James Brown’s Soul Power) already indicate that JNDs for simple detection of asynchrony in a given instrument layer (guitar, bass, drums [hi-hat, kick, snare]) exceed those predicted by the previous literature. This suggests that perhaps we are not as sensitive to certain forms of microrhythmic nuances in realistic musical contexts as previously thought. They also point to important differences in JND thresholds between musicians and non-musicians – individuals without musical training appear to be significantly less sensitive to microrhythmic nuances than musicians – as well as between percussive and stringed instruments – we appear to be more sensitive to asynchronies produced by sharper, impulsive drum sounds, as opposed to wider, smoother ones such as those of the electric bass and guitar. These latter findings in particular add to the growing awareness in the field of microrhythm studies that sound-related features related to timbre are fundamental to the perception and production of timing in groove-based contexts (Câmara et al. 2020a; 2020b). Different methodological approaches and challenges will also be discussed, with focus on how different procedures/tasks (e.g. directly comparing two grooves – one with, and one without, asynchrony – then identifying the one with asynchrony [2AFC], as opposed to simply listening to one groove, then identifying whether asynchronies were present or not [Yes/No]) can further affect JND timing thresholds and ultimately provide quite different answers as to what extent ‘microrhythm matters’ perceptually to us as listeners.

• Anne Danielsen, Ragnhild Brøvig, Guilherme Schmidt Câmara, Mari Romarheim Haugen, Mats Sigvard Johansson & Justin London (2023). There’s more to timing than time: Investigating sound–timing interaction across disciplines and cultures. Full text in Research Archive
• Guilherme Schmidt Câmara, Connor Spiech & Anne Danielsen (2023). To asynchrony and beyond: In search of more ecological perceptual heuristics for microrhythmic structures in groove-based music. Full text in Research Archive Show summary

  There is currently a gap in rhythm and timing research regarding how we perceive complex acoustic stimuli in musical contexts. Many studies have investigated timing acuity in non-musical contexts involving simple rhythmic sequences comprised of clicks or sine waves. However, the extent to which these results transfer to our perception of microrhythmic nuances in multilayered musical contexts rife with complex instrumental sounds remains poorly understood. In this talk we will present an overview of a planned series of just-noticeable difference (JND) experiments that will generate ecologically valid perceptual heuristics regarding timing discrimination thresholds. The aim is to investigate the extent to which microrhythmic timing and sonic nuances are perceived in groove-based music and connect these heuristics to the pleasurable urge to move in groove-based contexts, as well as acoustic (e.g., intensity, duration, frequency) and musical features (e.g., tempo, genre), and listener factors (e.g. musical training, stylistic familiarity). Overall, we expect timing thresholds to be higher for polyphonic/musical than for monotonic/non-musical stimuli/contexts and higher for pulse attribution (whether one can perceive a “beat”; Madison & Merker 2002, Psychol Res) than for simple detection of asynchrony and anisochrony (whether one can perceive “rhythmic irregularities”). Thresholds will likely be modulated by intensity (Goebl & Parncutt 2002, ICMPC7), tempo (Friberg & Sundberg 1995, J Acous Soc Am), instrumentation (Danielsen et al. 2019, J Exp Psychol), and genre/stylistic conventions (Câmara & Danielsen 2019, Oxford). Musically trained/stylistically familiar listeners may also display style-typical sensitivity to microrhythmic manipulations (Danielsen et al. 2021 Atten Percept Psychophys; Jakubowski et al. 2022; Cogn). In terms of subjective experience, we expect that onset asynchrony exaggerations will likely elicit lower pleasure and movement ratings compared to performances with idiomatic timing profiles (Senn et al. 2018, PLoS One). Higher ratings should also be biased in favor of familiar styles (Senn et al. 2021) and rhythmic patterns that do not engender excessive metrical ambiguity are likely to elicit higher ratings (Spiech et al. 2022, preprint; Witek et al. 2014, PLoS One).

• Guilherme Schmidt Câmara, Georgios Sioros, Anne Danielsen, Kristian Nymoen & Mari Romarheim Haugen (2023). Sound-producing actions in guitar performance of groove-based microrhythm. Full text in Research Archive Show summary

  This study 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 (neither 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).

• Anne Danielsen, Ragnhild Brøvig, Guilherme Schmidt Câmara, Mari Romarheim Haugen, Mats Sigvard Johansson & Justin London (2023). Microrhythm depends on sound qualities: Investigating sound–timing interaction across disciplines and cultures. Full text in Research Archive
• Guilherme Schmidt Câmara, Anne Danielsen & Kjell Andreas Oddekalv (2023). Funky rhythms – broken beats! Kulturelle og estetiske perspektiver på groove-basert musikk. Full text in Research Archive
• Guilherme Schmidt Câmara (2022). This is (not) fine - Reflections and Reccomendations of a post-PhD Post-Doc. Full text in Research Archive
• Connor Spiech, Mikael Hope, Guilherme Schmidt Câmara, Georgios Sioros, Tor Endestad & Bruno Laeng [Show all 7 contributors for this article] (2022). PredicTAPbility: Sensorimotor Synchronization Increases Groove. Full text in Research Archive
• Anne Danielsen, Guilherme Schmidt Câmara, Olivier Lartillot, Sabine Liliana Leske & Connor Spiech (2022). Musical rhythm. Behavioural, computational and neurophysiological perspectives. Full text in Research Archive
• Guilherme Schmidt Câmara & Maria Lokna (2021). Intervju i Morgenbladet - "Kan man forske på hva som er groovy?". [Journal]. Morgenbladet. Full text in Research Archive
• Guilherme Schmidt Câmara, George Sioros & Anne Danielsen (2021). Mapping timing and intensity strategies in drum-kit performance via hierarchical clustering and phylogenetic visualizations. Full text in Research Archive Show summary

  Background and Aim: Findings from performance timing experiments have shown that drummers are able to systematically play stroke onsets significantly earlier and later than an instructed on-the-beat performance (Câmara et al., 2020; Danielsen et al., 2015), and purportedly able to further control the degree of onset asynchrony between the various constituent instruments of the drum-kit (Câmara and Danielsen, 2019). Previous investigations have focused on comparing average statistical trends of onset timing between timing styles across entire groups of drummers. In this study, we map performance strategies present at the individual participant level and categorize the different archetypical ways in which drummers express different timing styles. We focus on the onset asynchrony and intensity of strokes between drum-kit instruments, and in relation to a metrical grid, and hypothesize that drummers employ consistent strategies to achieve different desired timing styles, choosing different instruments (snare/kick/hi-hat) in the rhythmic pattern to generate in-sync, late, and early timing performances. Methods: In a previous experiment (Câmara et al., 2020), twenty-two drummers were instructed to play a basic “back-beat” pattern along to a metronome and a pre-recorded instrumental track in three different timing conditions: laid-back, on-the-beat, and pushed. Here, we conduct a hierarchical cluster analysis of various onset and intensity features in this data set, combined with phylogenetic tree visualizations to provide an overview of the strategies used by the drummers to distinguish laid-back/pushed from on-the-beat performances. Furthermore, we encode the features of the onset or intensity clusters into microtiming archetypes that visually summarize the general characteristics of the drummers’ strategy in each cluster. Results: Overall, three overarching onset strategies were used to distinguish pushed/laid-back from on-the-beat performances: (1) strong “general earliness/lateness” strategies: most instruments are consistently played earlier/later in time relative to the grid; (2) subtler “early/late flam” strategies: most instruments are played synchronously with the grid but at least one instrument is played distinctively early/late ; and (3) even subtler “ambiguously early/late compound sound” strategies: two instruments are played synchronously in relation to each other as a compound sound, but one instrument is played synchronous with the grid and the other is played early/late. While no clear intensity manipulation patterns emerged to exclusively distinguish laid-back/pushed timing, they serve as a means of enhancing or diminishing the effect of intentionally produced asynchronies. Conclusion: Results indicate that performers utilize a range of inter-instrument onset timing and intensity relationships to express microrhythmic feel in groove performance, that is, different drummers use different means to achieve the same desired feel. Implications: The novel methods developed in this study may be applied to analysis of commercial recordings to provide insight into the idiomatic timing–sound strategies of influential performers and/or genres/styles more generally. References: Câmara, G. S., & Danielsen, A. (2019). Groove. In A. Rehding & S. Rings (Eds.), The Oxford handbook of critical concepts in music theory (pp. 271–294). Oxford University Press. Câmara, G. S., Nymoen, K., Lartillot, O., & Danielsen, A. (2020). Timing Is Everything . . . or Is It? Effects of Instructed Timing Style, Reference, and Pattern on Drum Kit Sound in Groove-Based Performance. Music Perception, 38(1), 1–26. Danielsen, A., Waadeland, C. H., Sundt, H. G., & Witek, M. A. G. (2015). Effects of instructed timing and tempo on snare drum sound in drum kit performance. Journal of the Acoustical Society of America, 138(4), 2301–2316.

• Francesco Ganis, Sofia Dahl, Guilherme Schmidt Câmara & Anne Danielsen (2021). Beat precision and perceived danceability in drum grooves. Full text in Research Archive Show summary

  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.

• Guilherme Schmidt Câmara (2021). Trial Lecture for Ph.D. disputation: "How far can we predict aesthetic effects from physical properties within and beyond groove music, and what can different microrhythmic feels communicate to listeners?". Full text in Research Archive
• Guilherme Schmidt Câmara & Silje Pileberg (2021). New research could inspire experimental musicians. Full text in Research Archive
• Guilherme Schmidt Câmara (2021). Presentation and Summary of Ph.D. Project: "Timing Is Everything . . . Or Is It? Investigating Timing and Sound Interactions in the Performance of Groove-Based Microrhythm". Full text in Research Archive
• Mari Lilleslåtten, Guilherme Schmidt Câmara & Anne Danielsen (2020). Hva du synes er bra musikk avgjøres på noen tusendels sekunder. [Internet]. Forskning.no. Full text in Research Archive
• Guilherme Schmidt Câmara (2020). Original concert performance with funk/soul ensemble "Baba Soul & The Professors of Funk", Jazz Fest Trondheim 2020. Full text in Research Archive
• George Sioros, Guilherme Schmidt Câmara & Anne Danielsen (2019). Mapping Timing Strategies in Drum Performance. Full text in Research Archive
• George Sioros, Guilherme Schmidt Câmara, Anne Danielsen & Kristian Nymoen (2019). Timing and drummers’ movement: A novel methodology for performance analysis. Full text in Research Archive Show summary

  Timing is an important aspect of groove music. The relationship between musicians’ body motion in performance and timing is, however, as yet not well understood Timing and drummers’ movement: A novel methodology for performance analysis . In the present study we recorded movement of 20 drummers performing the same rhythmic pattern under four different timing instructions: natural, on- the-beat, laid-back and pushed. Motion capture data synchronized to audio recordings of their performances were collected as part of a larger experimental project. This presentation focuses on our method for analyzing motion capture data. The aim of the analysis is a) to identify common movement strategies for sub-groups of drummers, and b) to identify strategies for achieving the four different timing conditions across drummers. In this presentation we focus on the movement of the left arm, and particularly on the preparation and rebound phase of the snare strokes. To explore and analyze the data without statistically testing a priori hypotheses about specific performance techniques, we combined existing practices from different disciplines into a novel methodology. First, we reduce the data into motion templates (Müller and Röder 2006). We design a set of 22 binary features to describe the movement of the arm. Second, we perform a phylogenetic analysis of the motion templates, in which we identify clusters within each timing condition. A comparison between clusters reveals differences in the coordination of the participants’ movements that correspond to the different performance strategies. Preliminary analysis has shown distinct clusters within all timing conditions that differ in specific features. For instance, we observe three groups of participants within the “natural” condition that differ in the flexion of the wrist and elbow. Besides our findings we will present the details of the methodology, which can be applied in the study of music-related movements beyond the scope of this project.

• Guilherme Schmidt Câmara, Kristian Nymoen, Olivier Lartillot & Anne Danielsen (2019). Timing is Everything... Or is it? Part I: Effects of Instructed Timing and Reference on Guitar and Bass Sound in Groove Performance. Full text in Research Archive
• Guilherme Schmidt Câmara, Kristian Nymoen & Anne Danielsen (2019). Timing is Everything... Or is it? Part II: Effects of Instructed Timing Style and Timing Reference on Drum-Kit Sound in Groove Performance. Full text in Research Archive
• Guilherme Schmidt Câmara (2018). Presentation of preliminary findings: Effects of Instructed Timing on Guitar and Bass Sound in Groove Performance. Full text in Research Archive
• Guilherme Schmidt Câmara (2018). Presentation of Mocap Component of Performance Experiments from the Timing and Sound in Musical Microrhythm (TIME) project. Full text in Research Archive
• Guilherme Schmidt Câmara (2018). Original concert performance with funk/soul ensemble "Baba Soul & The Professors of Funk", Oslo World Music Festival 2018. Full text in Research Archive
• Charles Patrick Martin, Victor Evaristo Gonzalez Sanchez, Tejaswinee Kelkar, Agata Zelechowska, Stig Johan Berggren & Christina Hopgood [Show all 14 contributors for this article] (2017). Ensemble Metatone - Improvised Touchscreen Performance. Full text in Research Archive
• Anne Danielsen, Kristian Nymoen, Mari Romarheim Haugen & Guilherme Schmidt Câmara (2017). Project presentation: Timing and Sound in Musical Microrhythm (TIME). Full text in Research Archive
• Guilherme Schmidt Câmara, Anne Danielsen & Kristian Nymoen (2021). Timing Is Everything . . . Or Is It? Investigating Timing and Sound Interactions in the Performance of Groove-Based Microrhythm. Universitetet i Oslo. Full text in Research Archive Show summary

  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.

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