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Publications

Publications by Carlos Guedes

2018

A generative model for the characterization of musical rhythms

Authors
Sioros, G; Davies, MEP; Guedes, C;

Publication
JOURNAL OF NEW MUSIC RESEARCH

Abstract
We present a novel model for the characterization of musical rhythms that is based on the pervasive rhythmic phenomenon of syncopation. Syncopation is felt when the sensation of the regular beat or pulse in the music is momentarily disrupted; the feeling arises from breaking more expected patterns such as pickups (anacrusis) and faster events that introduce and bridge the notes articulated on the beats. Our model begins with a simple pattern that articulates a beat consistent with the metrical expectations of a listener. Any rhythm is then generated from a unique combination of transformations applied on that simple pattern. Each transformation introduces notes in off-beat positions as one of three basic characteristic elements: (1) syncopations, (2) pickup rhythmic figures and (3) faster notes that articulate a subdivision of the beat. The characterization of a pattern is based on an algorithm that discovers and reverses the transformations in a stepwise manner. We formalize the above transformations and present the characterization algorithm, and then demonstrate and discuss the model through the analysis of the main rhythmic pattern of the song Don't stop till you get enough' by Michael Jackson.

2017

A Hierarchical Harmonic Mixing Method

Authors
Bernardes, G; Davies, MEP; Guedes, C;

Publication
Music Technology with Swing - 13th International Symposium, CMMR 2017, Matosinhos, Portugal, September 25-28, 2017, Revised Selected Papers

Abstract
We present a hierarchical harmonic mixing method for assisting users in the process of music mashup creation. Our main contributions are metrics for computing the harmonic compatibility between musical audio tracks at small- and large-scale structural levels, which combine and reassess existing perceptual relatedness (i.e., chroma vector similarity and key affinity) and dissonance-based approaches. Underpinning our harmonic compatibility metrics are harmonic indicators from the perceptually-motivated Tonal Interval Space, which we adapt to describe musical audio. An interactive visualization shows hierarchical harmonic compatibility viewpoints across all tracks in a large musical audio collection. An evaluation of our harmonic mixing method shows our adaption of the Tonal Interval Space robustly describes harmonic attributes of musical instrument sounds irrespective of timbral differences and demonstrates that the harmonic compatibility metrics comply with the principles embodied in Western tonal harmony to a greater extent than previous approaches. © 2018, Springer Nature Switzerland AG.

2012

New interaction paradigms to fight the digital divide: a pilot case study regarding multi-touch technology

Authors
Carvalho, D; Bessa, M; Oliveira, L; Guedes, C; Peres, E; Magalhaes, L;

Publication
PROCEEDINGS OF THE 4TH INTERNATIONAL CONFERENCE ON SOFTWARE DEVELOPMENT FOR ENHANCING ACCESSIBILITY AND FIGHTING INFO-EXCLUSION (DSAI 2012)

Abstract
Information and Communication Technologies (ICTs) are considered a powerful tool for economic development and the growth of societies. However, instead of helping overcome society's inqualities caused by the digital era, they have instigated an increase of the people that rested aside of the information age. The digital divide refers to the difficulty info-excluded people have in keeping up with technological advances. This phenomenon was triggered by the rapid growth and dissemination of technological equipment, as a portion of society did not have the proper time or knowledge to adjust. This paper sets forth a new approach to help fight the Portuguese digital divide by presenting new ways of interaction. Resorting to multi-touch technology, we examine how this new natural interaction paradigm can have a positive influence in the struggle against info-exclusion. For this purpose, we present a multi-touch game envisioned to encourage and teach digitally excluded people on how to use an important and needed everyday equipment - the ATM (Automated Teller Machine) - as it is still avoided by some. We believe that our pilot case study can show preliminary results on how natural user interfaces may be beneficial to help overcome some difficulties enforced by the digital divide. We consider that our findings may be valuable to show a possible path of how the new natural user interfaces can help bring technology and people closer. After being asked about their user experience, the participants of this exploratory study agreed that the game encouraged them to explore more about new technologies. (C) 2012 The Authors. Published by Elsevier B.V. Selection and/or peer-review under responsibility of the Scientific Programme Committee of the 4th International Conference on Software Development for Enhancing Accessibility and Fighting Info-exclusion (DSAI 2012)

2012

GimmeDaBlues app for iOS: Overview and ongoing developments

Authors
Dias, R; Guedes, C;

Publication
SIGGRAPH Asia 2012 Symposium on Apps, SA 2012

Abstract
This paper presents an overview of the GimmeDaBlues app for iOS devices, by Sonicability Inc., which allows the user to play a jazz/blues quartet, playing trumpet and/or keyboard, while being automatically accompanied by a virtual bassist and drummer. The application can also be used as an educational tool as an automatic play-along generator, allowing the user to concentrate on style and timing issues, while the app automatically takes care of selecting the right notes and chords, or used as a handy mobile sketchbook, using the recording and exporting features. A brief survey on related musical apps currently available on the Apple App store will be presented, as well as ongoing developments to include in future versions. CR Categories: H.5.5 [Sound and Music Computing]: Modeling.

2011

Complexity driven recombination of midi loops

Authors
Sioros, G; Guedes, C;

Publication
Proceedings of the 12th International Society for Music Information Retrieval Conference, ISMIR 2011

Abstract
An algorithm and a software application for recombining in real time MIDI drum loops that makes use of a novel analysis of rhythmic patterns that sorts them in order of their complexity is presented. We measure rhythmic complexity by comparing each rhythmic pattern found in the loops to a metrical template characteristic of its time signature. The complexity measure is used to sort the MIDI loops prior to utilizing them in the recombination algorithm. This way, the user can effectively control the complexity and variation in the generated rhythm during performance. © 2011 International Society for Music Information Retrieval.

2012

On measuring syncopation to drive an interactive music system

Authors
Sioros, G; Holzapfel, A; Guedes, C;

Publication
Proceedings of the 13th International Society for Music Information Retrieval Conference, ISMIR 2012

Abstract
In this paper we address the problem of measuring syncopation in order to mediate a musically meaningful interaction between a live music performance and an automatically generated rhythm. To this end we present a simple, yet effective interactive music system we developed. We shed some light on the complex nature of syncopation by looking into MIDI data from drum loops and whole songs. We conclude that segregation into individual rhythmic layers is necessary in order to measure the syncopation of a music ensemble. This implies that measuring syncopation on polyphonic audio signals is not yet tractable using the current state-of-the-art in audio analysis. © 2012 International Society for Music Information Retrieval.

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