‘The Sonata Type Tree’, Klang! A Music Theory & Analysis Blog

The Sonata Type Tree is an interactive tree diagram that I have created to visually represent James Hepokoski and Warren Darcy’s rotationally-defined Sonata Types 1, 2, 3 and 4, as theorised in Elements of Sonata Theory: Norms, Types, and Deformations in the Late Eighteenth-Century Sonata. The Tree can be used as a pedagogical or research tool to investigate the alternative trajectories of each type including the points that they converge and diverge. Musical time is represented from the top to the bottom of the diagram with tonic and non-tonic keys represented by black and white circles, respectively. This particular use of space allows for different ‘pathways’ through the types to be represented simultaneously as forking ‘branches’ of the tree. It differs from the use of diagrammatic space in Elements of Sonata Theory, where musical time unfolds horizontally, with tonal space aligned with vertical space (see p. 16).

I hope this diagram might be used as an introduction to the Sonata Types for students, musicologists, and anyone else who is interested in musical form.