Computational Modeling in Python for the Analysis of Choros: Hybrid Techniques for Pattern Extraction in Brazilian Popular Music

• Rafael Mitsuru Yasuda Unicamp

DOI: https://doi.org/10.5753/sbcm.2025.13682

Resumo

This article proposes a hybrid methodology for the computational analysis of the works of Aníbal Augusto Sardinha (Garoto), recognized as one of the most significant figures of instrumental Brazilian choro. The approach integrates symbolic and acoustic analysis procedures utilizing the Python libraries music21 and librosa, enabling automated extraction of structural and expressive parameters from digitized scores and historical recordings. The symbolic corpus is based on the Songbook Choros de Garoto (SESC/IMS), encompassing approximately fifty pieces converted into the MusicXML format. Whenever available, original recordings by Garoto are employed for acoustic analysis, allowing investigation of interpretative aspects such as dynamics, timbre, and tempo. The methodology includes the extraction of tonalities, structural forms, harmonic progressions, melodic n-grams, Mel-frequency cepstral coefficients (MFCCs), chromagrams, and energy curves. Symbolic and acoustic data are integrated into a tabular structure using the pandas library, facilitating exploratory analysis through techniques such as Principal Component Analysis (PCA) and t-Distributed Stochastic Neighbor Embedding (t-SNE). This study represents the initial stage of ongoing doctoral research and aims to contribute to the systematization of computational tools for stylistic studies of Brazilian popular music.

Referências

ALMADA, Carlos de L.; PROJETO MPB. Arranjo; Harmonia funcional; Contraponto em música popular; A harmonia de Jobim; A melodia de Jobim. Rio de Janeiro: UFRJ, 2023. Available at: [link]. Accessed: June 10, 2025.

ALMEIDA, Aline Z. Verde e amarelo em preto e branco: as impressões do choro no piano brasileiro. Master’s Dissertation (Music) – Instituto de Artes, Universidade Estadual de Campinas, Campinas, 1999. Available at: [link]. Accessed: June 10, 2025.

CUTHBERT, Michael S.; ARIZA, Christopher. music21: A toolkit for computer-aided musicology and symbolic music data. In: ISMIR 2010 – International Society for Music Information Retrieval Conference. Proceedings […]. New York: ISMIR, 2010.

KRUMHANSL, Carol L. Rhythm and pitch in music cognition. In: DOWLING, W. Jay; TILLMANN, Barbara (Eds.). Cognitive musicianship. Oxford: Oxford University Press, 2000. p. 1–20.

LIVINGSTON-ISENHOUR, Tamara; GARCIA, Thomas. Choro: a social history of a Brazilian popular music. Bloomington: Indiana University Press, 2005.

LOUREIRO, Paulo H. Corpus e análise estilística em música popular brasileira. São Paulo: Editora, 2003.

MCFEE, Brian et al. librosa: audio and music signal analysis in Python. In: SCIPY 2015 – 14th Python in Science Conference. Proceedings […]. Austin: SciPy, 2015. p. 18–25.

MOSS, Fabio C.; SOUZA, Wagner F.; ROHRMEIER, Martin. Harmony and form in Brazilian choro: a corpus-driven approach to musical style analysis. Journal of New Music Research, London, v. 49, n. 1, p. 1–22, 2020. DOI: 10.1080/09298215.2019.170722

MÜLLER, Meinard. Fundamentals of music processing: audio, analysis, algorithms, applications. Cham: Springer, 2015.

RAMALHO, Carolina R. G. Composição, interpretação e identidade na “Chorata No. 1” de Carlos Almada: contribuições e reflexões sobre oralidade e escrita do choro. In: CARVALHO, F. S.; NOGUEIRA, D. R. (Eds.). Discussões interdisciplinares no campo das ciências humanas. Recife: EdUFPE, 2020. p. 81–99.

SANDRONI, Carlos. Feitiço decente: transformações do samba no Rio de Janeiro (1917–1933). Rio de Janeiro: Jorge Zahar, 2001.

VALENTE, Paulo V. Transformações do choro no século XXI: estruturas, performances e identidade. Doctoral Thesis (Music) – Escola de Comunicações e Artes, Universidade de São Paulo, São Paulo, 2014. Available at: [link]. Accessed: June 10, 2025.