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Human-Centred Artificial Intelligence in Sound Perception and Music Composition

Authors:
  • Music Academy “Studio Musica”
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Abstract

Previous algorithms created for the harmonization of a melody have highlighted difficulties in finding a solution that could be significant and important not only from the point of view of listening but also from that of composition, that is, also respecting the rules of musical grammar that tradition handed down to us. This article describes a model for the harmonization of melody (non-modulating) derived from common concepts in music theory (such as Schenker’s theory) applied in compliance with the rules of musical grammar. The fundamental structure is characterized by a self-learning system based: on the Markovian stochastic process, for the definition of rules both for the concatenation of the chords and for the correct melodic movement of the sounds between two consecutive chords; on the Viterbi algorithm, for identifying the correct chord for each sound of the melody. The core of the algorithm allows the sounds of each chord to follow a correct trend (ascending or descending) such as to give each of them the real decisive impulse (which every listener is able to recognize). Examples of musical fragments harmonized in this way show that the apparatus of the composition rules and that of the listening rules must be thought of as coinciding (or at least partially in possession of common elements).

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Conference Paper
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Conference Paper
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Chapter
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Chapter
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Chapter
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Evolutionary Music Composer integrating Formal Grammar
  • Y M Khalifa
  • J Begovic
  • B Khan
  • A Wisdom
  • M B Al-Mourad
Khalifa, Y.M., Begovic, J., Khan, B., Wisdom, A., Al-Mourad, M.B. (2007). Evolutionary Music Composer integrating Formal Grammar. In: Elleithy, K. (eds) Advances and Innovations in Systems, Computing Sciences and Software Engineering. Springer, Dordrecht.
Modelling the syntax of north Indian melodies with a generalized graph grammar
  • C Finkensiep
  • R Widdess
  • M Rohrmeier
Finkensiep, C., Widdess, R., Rohrmeier, M. (2019). Modelling the syntax of north Indian melodies with a generalized graph grammar. In Proceedings of the 20 th International Society for Music Information Retrieval Conference (IS-MIR), pages 426-469.
Lezioni di armonia complementare
  • B Coltro
Coltro, B. (1997). Lezioni di armonia complementare. Ed. Zanibon
Automatic stylistic composition of Bach chorales with deep LSTM
  • F T Liang
  • M Gotham
Liang, F.T., Gotham, M. (2017). Automatic stylistic composition of Bach chorales with deep LSTM. In Proc. of International Society for Music Information Retrieval Conference, 449-456. Suzhou, China: ISMIR.
Bach Doodle: Approachable music composition with machine learning at scale
  • C Z A Huang
  • C Hawthorne
  • A Roberts
  • M Dinculescu
  • J Wexler
  • L Hong
  • J Howcroft
Huang, C. Z. A., Hawthorne, C., Roberts, A., Dinculescu, M., Wexler, J., Hong, L., and Howcroft, J. (2019). Bach Doodle: Approachable music composition with machine learning at scale. In Proceedings of the 18th International Society for Music Information Retrieval Conference (ISMIR), pages 793-800.
Hidden structure: music analysis using computers
  • D Cope
Cope, D. (2009). Hidden structure: music analysis using computers. AR Editions, Inc..
Theory and Harmony. Univ of California Pr
  • A Schoenberg
A. Schoenberg (1992). Theory and Harmony. Univ of California Pr; Reprint edition.
New Direct ion in Music Human-Computer Interaction. Book
  • S Holand
  • T Mudd
  • K Wilkie-Mckenna
  • A Mcpherson
  • M M Wanderley
Holand, S., Mudd, T., Wilkie-McKenna, K., McPherson, A., Wanderley, M.M. (2019). New Direct ion in Music Human-Computer Interaction. Book. Springer Cham.
Propositions pour un module transformationnel musicale
  • R Cooper
Cooper, R. (1973). Propositions pour un module transformationnel musicale. Musique enJeu, No. 10, pp. 70-88.
Musical Structure and Knowledge Representation
  • R West
  • P Howell
West, R., Howell, P., Cross. I (1991). Musical Structure and Knowledge Representation. In Representing Musical Structure. Eds. P. Howell, R. West and I. Cross, London: Academic Press, 1991, pp. 1-30.
La teoria semplificata dell'armonia di Hugo Riemann
  • M Giustini
Giustini, M. (2014). La teoria semplificata dell'armonia di Hugo Riemann. Ed. De Sono-Albisani.
Filosofia della musica
  • G Piana
Piana, G. (2013). Filosofia della musica. Ed. Guerini e Associati.