Adapting the Concept of Proportio to Rhythm in the Ars subtilior: Ugolino da Orvieto’s Compositions and his Statements on Proportion Signs in Codex Casanatense 2151

Abstract

Music manuscripts as well as music treatises from the early fifteenth century bear witness to major adaptations in music notation. The compositions of the so-called Ars subtilior feature notational innovations (e.g. new note shapes, notes in differently coloured ink, and proportion signs) which enable the depiction of complex rhythms. Simultaneously, discussions of notational innovations appear in music treatises, which were used in contexts of teaching and learning. This paper aims to investigate to what extent the adaptations in music treatises and compositions are interrelated, focusing on the manuscript Rome, Biblioteca Casanatense, 2151, which transmits three songs as well as the music treatise Declaratio musicae disciplinae. Both songs and treatise are attributed to the Italian music theorist and composer Ugolino da Orvieto (c. 1380–1452). A comparison of proportion signs contained in Ugolino’s songs and his statements on music notation will allow us to explore the question whether teachings on music reflect actual notational practice and vice versa.