A Computational Investigation of Melodic Contour Stability in Jewish Torah Trope Performance Traditions

The cantillation signs of the Jewish Torah trope are of particular interest to chant scholars interested in the gradual transformation of oral music performance into notation. Each sign, placed above or below the text, acts as a “melodic idea” which either connects or divides words in order to clarify the syntax, punctuation and, in some cases, meaning of the text. Unlike standard music notation, the interpretations of each sign are flexible and influenced by regional traditions, practices of given Jewish communities, larger musical influences beyond Jewish communities, and improvisatory elements incorporated by a given reader. In this paper we describe our collaborative work in developing and using computational tools to assess the stability of melodic formulas of cantillation signs based on two different performance traditions. We also show that a musically motivated alignment algorithm obtains better results than the more commonly used dynamic time warping method for calculating similarity between pitch contours. Using a participatory design process our team, which includes a domain expert, has developed an interactive web-based interface that enables researches to explore aurally and visually chant recordings and explore the relations between signs, gestures and musical representations.