Timespan Intervals
Jason Yust · Oxford University Press eBooks · 2018
David Lewin’s concept of timespan interval is applied to theories of hypermeter and rhythmic structure. The special property of timespan intervals is that the distances between them are measured relative to their lengths. They are therefore useful for equating hierarchical structures of timespans appearing at different levels of rhythmic structure, as an analysis of hemiolas in the F major prelude J.S. Bach’s Well-Tempered Clavier book I shows. A system of transformations is defined for navigating hierarchical networks of timespans, including translations, containment relations, and projections. The operations used to define rhythmic classes (swing, squeeze, syncopation, and meter change) are defined in terms of extensions and truncations applied within a structural network.