Browsing by Author "Manzara, Leonard C."

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    COMPARING HUMAN AND COMPUTATIONAL MODELS OF MUSIC PREDICTION
    (1992-05-01) Witten, Ian H.; Manzara, Leonard C.; Conklin, Darrell
    The information content of each successive note in a piece of music is not an intrinsic musical property but depends on the listener's own model of a genre of music. Human listeners' models can be elicited by having them guess successive notes and assign probabilities to their guesses by gambling. Computational models can be constructed by developing a structural framework for prediction, and "training" the system by having it assimilate a corpus of sample compositions and adjust its internal probability estimates accordingly. These two modeling techniques turn out to yield remarkably similar values for the information content, or "entropy," of the Bach chorale melodies. While previous research has concentrated on the overall information content of whole pieces of music, the present study evaluates and compares the two kinds of model in fine detail. Their predictions for two particular chorale melodies are analyzed on a note-by-note basis, and the smoothed information profiles of the chorales are examined and compared. Apart from the intrinsic interest of comparing human with computational models of music, several conclusions are drawn for the improvement of computational models.
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    ON THE ENTROPY OF MUSIC: AN EXPERIMENT WITH BACH CHORALE MELODIES
    (1991-12-01) Manzara, Leonard C.; Witten, Ian H.; James, Mark
    The information content, or "entropy", of a piece of music cannot be determined in the abstract, but depends on the listener's familiarity with, and knowledge of, the genre to which it belongs. This paper describes an experiment designed to investigate human listeners' models of music by having them guess successive notes in a piece. The experiment was administered by a computer program, and in order to elicit subjective probabilities, listeners gambled on the notes they guessed. The study was restricted to the music of the Bach Chorales, and, in particular, on the succession of pitches that comprise the melody--although our methodology is also generally applicable to other musical parameters, and to other genres. A tournament was held, with categories of novice, intermediate, and expert musician. As well as providing an overall measure of entropy for each of two chorale melodies, the results yield entropy profiles for the individual chorales. These give an objective, scientifically repeatable record of the note-by-note information content of the melodies, which can be interpreted musically in terms of expectation, suspense, and resolution in the music.