M. Bazant, Ousmane Kodio, Alexander E. Cohen, Kasim Khan, Zongyu Gu, J. M. Bush
Graphical Abstract Abstract A new guideline for mitigating indoor airborne transmission of COVID-19 prescribes a limit on the time spent in a shared space with an infected individual (Bazant & Bush, Proceedings of the National Academy of Sciences of the United States of America, vol. 118, issue 17, 2021, e2018995118). Here, we rephrase this safety guideline in terms of occupancy time and mean exhaled carbon dioxide (${rm CO}_{2}$) concentration in an indoor space, thereby enabling the use of ${rm CO}_{2}$ monitors in the risk assessment of airborne transmission of respiratory diseases. While ${rm CO}_{2}$ concentration is related to airborne pathogen concentration (Rudnick & Milton, Indoor Air, vol. 13, issue 3, 2003, pp. 237–245), the guideline developed here accounts for the different physical processes affecting their evolution, such as enhanced pathogen production from vocal activity and pathogen removal via face-mask use, filtration, sedimentation and deactivation. Critically, transmission risk depends on the total infectious dose, so necessarily depends on both the pathogen concentration and exposure time. The transmission risk is also modulated by the fractions of susceptible, infected and immune people within a population, which evolve as the pandemic runs its course. A mathematical model is developed that enables a prediction of airborne transmission risk from real-time ${rm CO}_{2}$ measurements. Illustrative examples of implementing our guideline are presented using data from ${rm CO}_{2}$ monitoring in university classrooms and office spaces.
{"title":"Monitoring carbon dioxide to quantify the risk of indoor airborne transmission of COVID-19","authors":"M. Bazant, Ousmane Kodio, Alexander E. Cohen, Kasim Khan, Zongyu Gu, J. M. Bush","doi":"10.1017/flo.2021.10","DOIUrl":"https://doi.org/10.1017/flo.2021.10","url":null,"abstract":"Graphical Abstract Abstract A new guideline for mitigating indoor airborne transmission of COVID-19 prescribes a limit on the time spent in a shared space with an infected individual (Bazant & Bush, Proceedings of the National Academy of Sciences of the United States of America, vol. 118, issue 17, 2021, e2018995118). Here, we rephrase this safety guideline in terms of occupancy time and mean exhaled carbon dioxide (${rm CO}_{2}$) concentration in an indoor space, thereby enabling the use of ${rm CO}_{2}$ monitors in the risk assessment of airborne transmission of respiratory diseases. While ${rm CO}_{2}$ concentration is related to airborne pathogen concentration (Rudnick & Milton, Indoor Air, vol. 13, issue 3, 2003, pp. 237–245), the guideline developed here accounts for the different physical processes affecting their evolution, such as enhanced pathogen production from vocal activity and pathogen removal via face-mask use, filtration, sedimentation and deactivation. Critically, transmission risk depends on the total infectious dose, so necessarily depends on both the pathogen concentration and exposure time. The transmission risk is also modulated by the fractions of susceptible, infected and immune people within a population, which evolve as the pandemic runs its course. A mathematical model is developed that enables a prediction of airborne transmission risk from real-time ${rm CO}_{2}$ measurements. Illustrative examples of implementing our guideline are presented using data from ${rm CO}_{2}$ monitoring in university classrooms and office spaces.","PeriodicalId":93752,"journal":{"name":"Flow (Cambridge, England)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41378939","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rohit Singhal, S. Ravichandran, R. Govindarajan, Sourabh S. Diwan
Abstract The SARS-CoV-2 is transmitted not only through coughing, but also through breathing, speaking or singing. We perform direct numerical simulations of the turbulent transport of potentially infectious aerosols in short conversations, involving repetitive phrases separated by quiescent intervals. We estimate that buoyancy effects due to droplet evaporation are small, and neglect them. A two-way conversation is shown to significantly reduce the aerosol exposure compared with a relative monologue by one person and relative silence of the other. This is because of the ‘cancelling’ effect produced by the two interacting speech jets. Unequal conversation is shown to significantly increase the infection risk to the person who talks less. Interestingly, a small height difference is worse for infection spread, due to reduced interference between the speech jets, than two faces at the same level. For small axial separation, speech jets show large oscillations and reach the other person intermittently. We suggest a range of lateral separations between two people to minimize transmission risk. A realistic estimate of the infection probability is provided by including exposure through the eyes and mouth, in addition to the more common method of using inhaled virions alone. We expect that our results will provide useful inputs to epidemiological models and to disease management.
{"title":"Virus transmission by aerosol transport during short conversations","authors":"Rohit Singhal, S. Ravichandran, R. Govindarajan, Sourabh S. Diwan","doi":"10.1017/flo.2022.7","DOIUrl":"https://doi.org/10.1017/flo.2022.7","url":null,"abstract":"Abstract The SARS-CoV-2 is transmitted not only through coughing, but also through breathing, speaking or singing. We perform direct numerical simulations of the turbulent transport of potentially infectious aerosols in short conversations, involving repetitive phrases separated by quiescent intervals. We estimate that buoyancy effects due to droplet evaporation are small, and neglect them. A two-way conversation is shown to significantly reduce the aerosol exposure compared with a relative monologue by one person and relative silence of the other. This is because of the ‘cancelling’ effect produced by the two interacting speech jets. Unequal conversation is shown to significantly increase the infection risk to the person who talks less. Interestingly, a small height difference is worse for infection spread, due to reduced interference between the speech jets, than two faces at the same level. For small axial separation, speech jets show large oscillations and reach the other person intermittently. We suggest a range of lateral separations between two people to minimize transmission risk. A realistic estimate of the infection probability is provided by including exposure through the eyes and mouth, in addition to the more common method of using inhaled virions alone. We expect that our results will provide useful inputs to epidemiological models and to disease management.","PeriodicalId":93752,"journal":{"name":"Flow (Cambridge, England)","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-03-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48061666","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
I. Gabay, Federico Paratore, E. Boyko, A. Ramos, A. Gat, M. Bercovici
Graphical Abstract Abstract We present a theoretical model and experimental demonstration of thin liquid film deformations due to a dielectric force distribution established by surface electrodes. We model the spatial electric field produced by a pair of parallel electrodes and use it to evaluate the stress on the liquid–air interface through Maxwell stresses. By coupling this force with the Young–Laplace equation, we obtain the deformation of the interface. To validate our theory, we design an experimental set-up which uses microfabricated electrodes to achieve spatial dielectrophoretic actuation of a thin liquid film, while providing measurements of microscale deformations through digital holographic microscopy. We characterize the deformation as a function of the electrode-pair geometry and film thickness, showing very good agreement with the model. Based on the insights from the characterization of the system, we pattern conductive lines of electrode pairs on the surface of a microfluidic chamber and demonstrate the ability to produce complex two-dimensional deformations. The films can remain in liquid form and be dynamically modulated between different configurations or polymerized to create solid structures with high surface quality.
{"title":"Shaping liquid films by dielectrophoresis","authors":"I. Gabay, Federico Paratore, E. Boyko, A. Ramos, A. Gat, M. Bercovici","doi":"10.1017/flo.2021.13","DOIUrl":"https://doi.org/10.1017/flo.2021.13","url":null,"abstract":"Graphical Abstract Abstract We present a theoretical model and experimental demonstration of thin liquid film deformations due to a dielectric force distribution established by surface electrodes. We model the spatial electric field produced by a pair of parallel electrodes and use it to evaluate the stress on the liquid–air interface through Maxwell stresses. By coupling this force with the Young–Laplace equation, we obtain the deformation of the interface. To validate our theory, we design an experimental set-up which uses microfabricated electrodes to achieve spatial dielectrophoretic actuation of a thin liquid film, while providing measurements of microscale deformations through digital holographic microscopy. We characterize the deformation as a function of the electrode-pair geometry and film thickness, showing very good agreement with the model. Based on the insights from the characterization of the system, we pattern conductive lines of electrode pairs on the surface of a microfluidic chamber and demonstrate the ability to produce complex two-dimensional deformations. The films can remain in liquid form and be dynamically modulated between different configurations or polymerized to create solid structures with high surface quality.","PeriodicalId":93752,"journal":{"name":"Flow (Cambridge, England)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43600907","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Leidenfrost drops were recently found to host strong dynamics. In the present study, we investigate both experimentally and theoretically the flow structures and stability inside a Leidenfrost water drop as it evaporates, starting with a large puddle. As revealed by infrared mapping, the drop base is warmer than its apex by typically 10 $^{circ }$C, which is likely to trigger bulk thermobuoyant flows and Marangoni surface flows. Tracer particles unveil complex and strong flows that undergo successive symmetry breakings as the drop evaporates. We investigate the linear stability of the base flows in a non-deformable, quasi-static, levitating drop induced by thermobuoyancy and the effective thermocapillary surface stress, using only one adjustable parameter. The stability analysis of nominally axisymmetric thermoconvective flows, parametrized by the drop radius $R$, yields the most unstable, thus, dominant, azimuthal modes (of wavenumber $m$). Our theory predicts well the radii $R$ for the mode transitions and cascade with decreasing wavenumber from $m=3,, m=2$, down to $m=1$ (the eventual rolling mode that entails propulsion) as the drop shrinks in size. The effect of the escaping vapour is not taken into account here, which may further destabilize the inner flow and couple to the liquid/vapour interface to give rise to motion (Bouillant et al. Nat. Phys., vol. 14 (12), 2018, pp. 1188–1192; Brandão & Schnitzer Physical Review Fluids, vol. 5 (9), 2020, 091601).
{"title":"Leidenfrost flows: instabilities and symmetry breakings","authors":"E. Yim, A. Bouillant, David Qu'er'e, F. Gallaire","doi":"10.1017/flo.2022.5","DOIUrl":"https://doi.org/10.1017/flo.2022.5","url":null,"abstract":"Abstract Leidenfrost drops were recently found to host strong dynamics. In the present study, we investigate both experimentally and theoretically the flow structures and stability inside a Leidenfrost water drop as it evaporates, starting with a large puddle. As revealed by infrared mapping, the drop base is warmer than its apex by typically 10 $^{circ }$C, which is likely to trigger bulk thermobuoyant flows and Marangoni surface flows. Tracer particles unveil complex and strong flows that undergo successive symmetry breakings as the drop evaporates. We investigate the linear stability of the base flows in a non-deformable, quasi-static, levitating drop induced by thermobuoyancy and the effective thermocapillary surface stress, using only one adjustable parameter. The stability analysis of nominally axisymmetric thermoconvective flows, parametrized by the drop radius $R$, yields the most unstable, thus, dominant, azimuthal modes (of wavenumber $m$). Our theory predicts well the radii $R$ for the mode transitions and cascade with decreasing wavenumber from $m=3,, m=2$, down to $m=1$ (the eventual rolling mode that entails propulsion) as the drop shrinks in size. The effect of the escaping vapour is not taken into account here, which may further destabilize the inner flow and couple to the liquid/vapour interface to give rise to motion (Bouillant et al. Nat. Phys., vol. 14 (12), 2018, pp. 1188–1192; Brandão & Schnitzer Physical Review Fluids, vol. 5 (9), 2020, 091601).","PeriodicalId":93752,"journal":{"name":"Flow (Cambridge, England)","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41829644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Graphical Abstract This study aims to leverage the relationship between fluid dynamic loading and resulting structural deformation to infer the incident flow speed from measurements of time-dependent structure kinematics. Wind tunnel studies are performed on cantilevered cylinders and trees. Tip deflections of the wind-loaded structures are captured in time series data, and a physical model of the relationship between force and deflection is applied to calculate the instantaneous wind speed normalized with respect to a known reference wind speed. Wind speeds inferred from visual measurements showed consistent agreement with ground truth anemometer measurements for different cylinder and tree configurations. These results suggest an approach for non-intrusive, quantitative flow velocimetry that eliminates the need to directly visualize or instrument the flow itself.
{"title":"Wind speed inference from environmental flow–structure interactions","authors":"Jennifer L. Cardona, K. Bouman, J. Dabiri","doi":"10.1017/flo.2021.3","DOIUrl":"https://doi.org/10.1017/flo.2021.3","url":null,"abstract":"Graphical Abstract This study aims to leverage the relationship between fluid dynamic loading and resulting structural deformation to infer the incident flow speed from measurements of time-dependent structure kinematics. Wind tunnel studies are performed on cantilevered cylinders and trees. Tip deflections of the wind-loaded structures are captured in time series data, and a physical model of the relationship between force and deflection is applied to calculate the instantaneous wind speed normalized with respect to a known reference wind speed. Wind speeds inferred from visual measurements showed consistent agreement with ground truth anemometer measurements for different cylinder and tree configurations. These results suggest an approach for non-intrusive, quantitative flow velocimetry that eliminates the need to directly visualize or instrument the flow itself.","PeriodicalId":93752,"journal":{"name":"Flow (Cambridge, England)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/flo.2021.3","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45986032","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract Current methods for fabricating lenses rely on mechanical processing of the lens or mould, such as grinding, machining and polishing. The complexity of these fabrication processes and the required specialized equipment prohibit rapid prototyping of optical components. This work presents a simple method, based on free-energy minimization of liquid volumes, which allows us to quickly shape curable liquids into a wide range of spherical and aspherical optical components, without the need for any mechanical processing. After the desired shape is obtained, the liquid can be cured to produce a solid object with nanometric surface quality. We provide a theoretical model that accurately predicts the shape of the optical components, and demonstrate rapid fabrication of all types of spherical lenses (convex, concave, meniscus), cylindrical lenses, bifocal lenses, toroidal lenses, doublet lenses and aspheric lenses. The method is inexpensive and can be implemented using a variety of curable liquids with different optical and mechanical properties. In addition, the method is scale invariant and can be used to produce even very large optical components, without a significant increase in fabrication time. We believe that the ability to easily and rapidly create optical components, without the need for complex and expensive infrastructure, will provide researchers with new affordable tools for fabricating and testing optical designs.
{"title":"Fluidic shaping of optical components","authors":"V. Frumkin, M. Bercovici","doi":"10.1017/flo.2021.1","DOIUrl":"https://doi.org/10.1017/flo.2021.1","url":null,"abstract":"Abstract Current methods for fabricating lenses rely on mechanical processing of the lens or mould, such as grinding, machining and polishing. The complexity of these fabrication processes and the required specialized equipment prohibit rapid prototyping of optical components. This work presents a simple method, based on free-energy minimization of liquid volumes, which allows us to quickly shape curable liquids into a wide range of spherical and aspherical optical components, without the need for any mechanical processing. After the desired shape is obtained, the liquid can be cured to produce a solid object with nanometric surface quality. We provide a theoretical model that accurately predicts the shape of the optical components, and demonstrate rapid fabrication of all types of spherical lenses (convex, concave, meniscus), cylindrical lenses, bifocal lenses, toroidal lenses, doublet lenses and aspheric lenses. The method is inexpensive and can be implemented using a variety of curable liquids with different optical and mechanical properties. In addition, the method is scale invariant and can be used to produce even very large optical components, without a significant increase in fabrication time. We believe that the ability to easily and rapidly create optical components, without the need for complex and expensive infrastructure, will provide researchers with new affordable tools for fabricating and testing optical designs.","PeriodicalId":93752,"journal":{"name":"Flow (Cambridge, England)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-05-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1017/flo.2021.1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46748042","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-24DOI: 10.1093/oso/9780190670412.003.0005
Mitchell Ohriner
Following Leonard B. Meyer’s distinction between stylistic and critical analysis, the first part of this chapter undertakes a stylistic analysis of flow in rap music, drawing on the models of accent, rhyme, groove, and groovy listening presented in Chapters 3 and 4 to characterize flow in the genre as a whole, as evidenced by the corpus constructed in Chapter 2. Features of flow discussed include speed, tempo, phrasing, rhyme patterning, groove class usage, adherence to groove classes, and groove typicality. The second part of the chapter pivots to critical analysis, examining the meanings of virtuosic flow in the rapping of the emcee Black Thought of The Roots (aka Tariq Trotter). By contextualizing Black Thought within the genre, the chapter shows his flow to be a combination of complexity and comprehensibility.
根据Leonard B. Meyer对风格分析和批评分析的区分，本章的第一部分对说唱音乐中的流进行了风格分析，利用第三章和第四章中提出的重音、押韵、律动和groovy听的模式，从整体上表征该类型的流，正如第二章构建的语料库所证明的那样。所讨论的流的特征包括速度、节奏、乐句、押韵模式、凹槽类的使用、对凹槽类的遵守以及凹槽的典型性。本章的第二部分以批判性分析为中心，考察了主持人Black Thought of The Roots(又名Tariq Trotter)说唱中艺术流的意义。通过将黑人思想置于该体裁的语境中，本章展示了他的写作流程是复杂性和可理解性的结合。
{"title":"Features of Flow in the Genre and the Artist","authors":"Mitchell Ohriner","doi":"10.1093/oso/9780190670412.003.0005","DOIUrl":"https://doi.org/10.1093/oso/9780190670412.003.0005","url":null,"abstract":"Following Leonard B. Meyer’s distinction between stylistic and critical analysis, the first part of this chapter undertakes a stylistic analysis of flow in rap music, drawing on the models of accent, rhyme, groove, and groovy listening presented in Chapters 3 and 4 to characterize flow in the genre as a whole, as evidenced by the corpus constructed in Chapter 2. Features of flow discussed include speed, tempo, phrasing, rhyme patterning, groove class usage, adherence to groove classes, and groove typicality. The second part of the chapter pivots to critical analysis, examining the meanings of virtuosic flow in the rapping of the emcee Black Thought of The Roots (aka Tariq Trotter). By contextualizing Black Thought within the genre, the chapter shows his flow to be a combination of complexity and comprehensibility.","PeriodicalId":93752,"journal":{"name":"Flow (Cambridge, England)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46143134","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-24DOI: 10.1093/oso/9780190670412.003.0008
Mitchell Ohriner
Throughout his career, Talib Kweli has been called an “off-beat rapper.” Despite that highly derogatory comment, this chapter connects Kweli’s non-alignment with the underlying beat to earlier Afro-diasporic rhythmic practices. Kweli’s voice moves away from the beat through four distinct processes: phase shifting, swinging, tempo shifting, and deceleration. The last of these, while a hallmark of the rhythm of speech, has little relationship to the rhythm of music with a mechanically regulated beat. By documenting the non-alignment between flow and beat in a particular track (“Get By”), the chapter shows the novel way in which Kweli inserts rupture into the flows of his verses, extending the aesthetic values of hip hop into the rhythms of his flow itself.
{"title":"Flow and Free Rhythm in Talib Kweli","authors":"Mitchell Ohriner","doi":"10.1093/oso/9780190670412.003.0008","DOIUrl":"https://doi.org/10.1093/oso/9780190670412.003.0008","url":null,"abstract":"Throughout his career, Talib Kweli has been called an “off-beat rapper.” Despite that highly derogatory comment, this chapter connects Kweli’s non-alignment with the underlying beat to earlier Afro-diasporic rhythmic practices. Kweli’s voice moves away from the beat through four distinct processes: phase shifting, swinging, tempo shifting, and deceleration. The last of these, while a hallmark of the rhythm of speech, has little relationship to the rhythm of music with a mechanically regulated beat. By documenting the non-alignment between flow and beat in a particular track (“Get By”), the chapter shows the novel way in which Kweli inserts rupture into the flows of his verses, extending the aesthetic values of hip hop into the rhythms of his flow itself.","PeriodicalId":93752,"journal":{"name":"Flow (Cambridge, England)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45479784","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-24DOI: 10.1093/oso/9780190670412.003.0007
Mitchell Ohriner
Previous analyses of and discourse on the relationship between flow and beat (i.e., the instrumental streams of a rap track) have mapped musical meaning flowing directionally from the beat to the flow. This chapter documents a wider range of relationships between flow and beat in the rapping of Black Thought, including flows that diverge from rather than converge with beats, and flows that converge with beats but with a conceptual or temporal distance. Since Black Thought performs with a live band (The Roots), the chapter also considers how changes to the beat in live performance affect the groove of his flow. As rap music presents an ontology far different from European classical music, one in which creative agencies multiply and authority frequently shifts, this chapter sketches an analytical method for a host of musics that do not exhibit the work concept of the classical score.
{"title":"Flow, Groove, and Beat in Black Thought","authors":"Mitchell Ohriner","doi":"10.1093/oso/9780190670412.003.0007","DOIUrl":"https://doi.org/10.1093/oso/9780190670412.003.0007","url":null,"abstract":"Previous analyses of and discourse on the relationship between flow and beat (i.e., the instrumental streams of a rap track) have mapped musical meaning flowing directionally from the beat to the flow. This chapter documents a wider range of relationships between flow and beat in the rapping of Black Thought, including flows that diverge from rather than converge with beats, and flows that converge with beats but with a conceptual or temporal distance. Since Black Thought performs with a live band (The Roots), the chapter also considers how changes to the beat in live performance affect the groove of his flow. As rap music presents an ontology far different from European classical music, one in which creative agencies multiply and authority frequently shifts, this chapter sketches an analytical method for a host of musics that do not exhibit the work concept of the classical score.","PeriodicalId":93752,"journal":{"name":"Flow (Cambridge, England)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45879646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2019-10-24DOI: 10.1093/oso/9780190670412.003.0002
Mitchell Ohriner
Over the course of his writing, Leonard B. Meyer distinguished between two kinds of music analysis: style analysis, which identifies the “rules of the game” operating in a collection of music, and critical analysis, which seeks to explain the choices of artists by identifying the range of possibilities they confront at each moment and interpreting the path they take. This chapter prepares for the critical analysis of flow in rap music by constructing a corpus of rap verses, taking care to document and maintain rap’s chronological, geographical, and stylistic diversity. The chapter also describes how primary constituents of flow (text, rhythm, and phrase) are digitally represented in the corpus.
{"title":"A Corpus for Rap Music Analysis","authors":"Mitchell Ohriner","doi":"10.1093/oso/9780190670412.003.0002","DOIUrl":"https://doi.org/10.1093/oso/9780190670412.003.0002","url":null,"abstract":"Over the course of his writing, Leonard B. Meyer distinguished between two kinds of music analysis: style analysis, which identifies the “rules of the game” operating in a collection of music, and critical analysis, which seeks to explain the choices of artists by identifying the range of possibilities they confront at each moment and interpreting the path they take. This chapter prepares for the critical analysis of flow in rap music by constructing a corpus of rap verses, taking care to document and maintain rap’s chronological, geographical, and stylistic diversity. The chapter also describes how primary constituents of flow (text, rhythm, and phrase) are digitally represented in the corpus.","PeriodicalId":93752,"journal":{"name":"Flow (Cambridge, England)","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2019-10-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42753981","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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