Popular music is a valued component of Brazilian national heritage because it reflects local traditions and produces records of current social and cultural organization. Despite the importance of popular music to Brazilian heritage, many sources of information regarding this music have interoperability problems and are unable to meet all users' information needs. Most systems for classifying musical information applied to Brazilian popular music are adaptations that hinder the management of this repertoire. In this article it is discussed a specific representation for Brazilian popular music in the form of a conceptual model in order to communicate its nuances and enable the derivation of application models for different areas, such as Museology and Librarianship.
This article presents a specific conceptual model for Brazilian popular music
representation, which aims to communicate its nuances and enable the derivation of
application models for different areas, such as Museology and Librarianship. The proposed
model expresses the nature of musical works in Brazilian popular music tradition and real
world situations in which those works are conceived, performed and recorded. The
represented conceptualization is built based on the study of the aforementioned conceptual
models and on a previous research [
For better expressivity, the model is represented in the well-founded OntoUML
language [
The conceptual model is presented in the form of OntoUML diagrams followed by textual explanations of the represented conceptualization. In order to reduce the number of elements and ease visualization, mediation and formal relation stereotypes are not shown. Not stereotyped relations linked to relatorKind classes and its specializations are mediations, while the remaining not stereotyped relations are formal.
Figure 1 presents a diagram with the arguably most important concepts in the model, the Work and its specializations. To explain the concept of Work, we borrow a fragment of F1 Work specification of FRBRoo model: “(the work) comprises distinct concepts or combinations of concepts identified in artistic and intellectual expressions, such as poems, stories or musical compositions. Such concepts may appear in the course of the coherent evolution of an original idea into one or more expressions that are dominated by the original idea” [IFLA 2015].
A MusicalWork relates to musical expressions, while a TextualWork relates to textual expressions. Musical works can be seen as “musical ideas”, something like a musical sound not expressed, as if someone could imagine it or play it internally in her mind. TextualWork was modeled as a kind and not a category in order to abstract the taxonomy of textual works, considered not important for this conceptualization.
It is important to draw a distinction between MusicalComposition, Song and Arrangement. A musical composition is a musical work which is considered original, or authorial in users’ point of view. It is mainly identified by a melody, that, even with some variations, can be used to identify its expressions (e.g., musical sounds, scores, etc.) as instances of the same “music”, even with no lyrics. Musical compositions and songs are considered original musical ideas (OriginalMusicalIdea).
A Song is a musical work which links a MusicalComposition to a TextualWork. A song is a music with lyrics. “A Garota de Ipanema”1 is a song with music by Antoˆnio Carlos Jobim and Portuguese lyrics by Vinicius de Moraes. The Lyrics was modeled as a role of a textual work in a song considering that different sorts of textual works can be used as lyrics. Usually the lyrics is written for the song, but it is not rare for a poem to be used as lyrics. One good example is the song “Canteiros” where Fagner composed a music for a poem by Cec´ılia Meireles. The music in the song was modelled as the role MusicalCompositionInSong. There is also the case where a song is made by adding a lyrics to an existing musical composition. In this conceptualization the song “A Garota de Ipanema” with Portuguese lyrics and “The Girl of Ipanema” with English lyrics by Norman Gimbel are different songs that share the same music (MusicalComposition). It is important to notice that a music to be considered a song must privilege the text. Instrumental music can use the human voice to compose the musical texture on the same level of other musical instruments, even when emitting words or isolated phrases, and still not be considered a song.
An Arrangement is a musical work whose author elaborates one (or more) original musical idea, in order to represent it in a given context or in a certain form. That context or form can be as diverse as an album recording of a band, a public performance, a representation in form of a musical notation for a specific orchestration, or a film soundtrack. The class BasicMusicalComponents represents the intrinsic musical elements in musical works (e.g., harmony, melody, rhythm, timbre, texture, etc.). Those elements are not modeled separately because they usually overlap. CompositionMusicalComponents consist primarily of the composition’s melody. They carry the minimum set of elements needed to group all arrangements made for that composition. On the other hand, the ArrangementMusicalComponents contain all musical components intended for its execution.
The arrangement is a central piece in the Brazilian popular music scenario. The expression of any musical work requires an arrangement, being this expression in the form of sound or any kind of musical notation. That conceptualization is represented by the category ArrangementExpression and its specializations MusicalSound and WrittenMusicalExpression. Musical compositions and songs need an arrangement to be expressed. For example, when someone makes a song and records a video for the Internet singing and playing a guitar, this person is expressing a song with its lyrics and musical composition through an arrangement for voice and guitar.
An arrangement is not always expressed in the form of musical notation (a common situation in this domain), nor its authorship is always registered or recognized. Many arrangements are made in the context of a recording session in a studio where the ar1Brazilian name for the original song “The Girl From Ipanema”. ranger and the performers interact informally. An arrangement exists even in the context of a group of performers playing together without previous preparation. In that case, the performers themselves are the arrangers.
Other concepts related to arrangements are shown in Figure 2. The first arrangement by which a song or a musical composition is made known is an original version. Other arrangements of the same original musical idea are considered derived versions. Most arrangements are made for one single original musical idea, however some others concatenate more than one original musical idea in the same arrangement (Medley). These medley versions are always derived. If an arrangement is made for at least one song, it is considered to be a sung version, otherwise it is an instrumental version.
The category MediumOfPerformance (MOP) represents any sort of media used
by an individual performer artist to express sound when playing in a performance.
Usually it is a musical instrument or the human voice, but it can be anything that can produce
sound as when Hermeto Pascoal plays his heartbeat or the whistle of a kettle. An
arrangement defines an Orchestration, which states the number and types of medium of
performances must be used (e.g., one singer and two guitars). The powerType
MediumOfPerformanceType represents all the possible types of MOP, so the orchestration can
prescribe kinds of MOP instead of MOP instances. An arrangement is made for any piano,
not a specific piano instance. This powerType plays the role
IntendedMediumOfPerformanceType in the orchestration. The attribute numberOfMOP indicates the number of
MOPs of that type should be used. The relation between MediumOfPerformanceType
and MOP follows the UML notation proposed by [
The musical Performance is shown in the diagram on Figure 3. A performance must be an IndividualPerformance (performed by only one IndividualPerformer) or a ColectivePerformance (when there are more than one musician playing). A collective performance is always composed by two or more individual performances. A Band is formed by two or more BandMember that can change over time. Its principle of identity does not depend on the variation of its members in time. One Person plays the role of an IndivdualPerformer when playing one or more MediumOfPerformance in an IndividualPerformance. The role PerformingBandMember is an individual performer that performs on behalf of a band.
The model represents the reality in such a way it can be more expressive and serve to a broader spectrum of applications. One example of that expressivity is the use of Powertypes to differentiate the instances of played instruments from their types. One application can be interested in the actual instance of the guitar played by Joa˜o Gilberto at the Carnegie Hall in 1962, while, for other application, knowing the kind of the played instrument is enough. Museum studies are interested in object instances, whereas bibliographical applications ignore this information.
A performance is held in one Place. It can occur in the context of a MusicalEvent. The PerformedSound is considered inherent to the performance. That sound can optionally be recorded to produce musical tracks (Track). Those tracks can be published in diverse media and formats, however concepts related to these publications are not covered by this model.
The diagram in Figure 4 depicts all authorship relations. All of those relations specialize the relatorKind Authorship. There is an authorship relation for each work with one or more authors, and each author can produce several works. The role Author is specialized according to the conceived work type.
The presented model has already shown its value by supporting better communication and analysis of the domain and should evolve to cover concepts such as bibliographical items, cultural context and musical genres. Other usages for this model may include the adequacy evaluation of other music information organization initiatives to this domain, and its use as a common conceptualization for semantic interoperability among heterogeneous data sources.
This research focus on Brazilian popular music, although several of its concepts seem to be common to other musical traditions. The adequacy of this model to other musical contexts will be object of future studies.
It is expected that this work might serve as a first formal description about Brazilian popular music and support the development of software applications, such as music digital libraries, in consonance with Brazilian culture and traditions.
IFLA (2017). IFLA Library Reference Model: A Conceptual Model for Bibliographic Information, Final Report. International Federation of Library Associations and Institutions.