A quantitative, parametric model of musical tension

Thesis (Ph. D.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2006.Includes bibliographical references (leaves [125]-132).This thesis presents a quantitative, parametric model for describing musical tension. While the phenomenon of tension is evident to listeners, it is difficult to formalize due to its subjective and multi-dimensional nature. The model is therefore derived from empirical data. Two experiments with contrasting approaches are described. The first experiment is an online test with short musical excerpts and multiple choice answers. The format of the test makes it possible to gather large amounts of data. The second study requires fewer subjects and collects real-time responses to musical stimuli. Both studies present test subjects with examples that take into account a number of musical parameters including harmony, pitch height, melodic expectation, dynamics, onset frequency, tempo, and rhythmic regularity. The goal of the first experiment is to confirm that the individual musical parameters contribute directly to the listener's overall perception of tension. The goal of the second experiment is to explore linear and nonlinear models for predicting tension given descriptions of the musical parameters for each excerpt. The resulting model is considered for potential incorporation into computer-based applications. Specifically, it could be used as part of a computer-assisted composition environment. One such application, Hyperscore, is described and presented as a possible platform for integration.by Morwaread M. Farbood.Ph.D

Hyperscore : a new approach to interactive, computer-generated music

Thesis (S.M.)--Massachusetts Institute of Technology, School of Architecture and Planning, Program in Media Arts and Sciences, 2001.Includes bibliographical references (leaves 78-81).This thesis discusses the design and implementation of Hyperscore, a computer-assisted composition system intended for users of all musical backgrounds. Hyperscore presents a unique graphical interface which takes input in the form of freehand drawing. The strokes in the drawing are mapped to structural and gestural elements in the music, allowing the user to describe the large scale-structure of a piece visually. Hyperscore's graphical notation also enables the depiction of musical ideas on a detailed level. Additional annotations around a main curve indicate the placement and emphasis of selected motives. These motives are short melodic fragments that are either composed by the user or selected from a set of pre-composed material. Changing qualitative aspects of the annotations such as texture and shape let the user alter different musical parameters. The ultimate goal of Hyperscore is to provide an intuitive, interactive graphical environment for creating and editing compositions.by Mary Farbood.S.M

Interpreting expressive performance through listener judgments of musical tension

This study examines listener judgments of musical tension for a recording of a Schubert song and its harmonic reduction. Continuous tension ratings collected in an experiment and quantitative descriptions of the piece’s musical features, include dynamics, pitch height, harmony, onset frequency, and tempo, were analyzed from two different angles. In the first part of the analysis, the different processing timescales for disparate features contributing to tension were explored through the optimization of a predictive tension model. The results revealed the optimal time windows for harmony were considerably longer (~22 s) than for any other feature (~1-4 s). In the second part of the analysis, tension ratings for the individual verses of the song and its harmonic reduction were examined and compared. The results showed that although the average tension ratings between verses were very similar, differences in how and when participants reported tension changes highlighted performance decisions made in the interpretation of the score, ambiguity in tension implications of the music, and the potential importance of contrast between verses and phrases. Analysis of the tension ratings for the harmonic reduction also provided a new perspective for better understanding how complex musical features inform listener tension judgments.<br/

The neural processing of hierarchical structure in music and speech at different timescales

Music, like speech, is a complex auditory signal that contains structures at multiple timescales, and as such a potentially powerful entry point into the question of how the brain integrates complex streams of information. Using an experimental design modeled after previous studies that used scrambled versions of a spoken story (Lerner, Honey, Silbert, & Hasson, 2011) and a silent movie (Hasson, Yang, Vallines, Heeger, & Rubin, 2008), we investigate whether listeners perceive hierarchical structure in music beyond short (~6 sec) time windows and whether there is cortical overlap between music and language processing at multiple timescales. Experienced pianists were presented with an extended musical excerpt scrambled at multiple timescales––by measure, phrase, and section––while measuring brain activity with functional magnetic resonance imaging (fMRI). The reliability of evoked activity, as quantified by inter-subject correlation of the fMRI responses was measured. We found that response reliability depended systematically on musical structural coherence, revealing a topographically organized hierarchy of processing timescales. Early auditory areas (at the bottom of the hierarchy) responded reliably in all conditions. For brain areas at the top of the hierarchy, the original (unscrambled) excerpt evoked more reliable responses than any of the scrambled excerpts, indicating that these brain areas process long-timescale musical structures, on the order of minutes. The topography of processing timescales was analogous with that reported previously for speech, but the timescale gradients for music and speech overlapped with one another only partially, suggesting that temporally analogous structures––words/measures, sentences/musical phrases, paragraph/sections––are processed separately