Medial Caesura, wherefore art thou? The Augmented-Sixth Chord as a Formal Initiator in 19th-Century Sonata Expositions

Graham Hunt, University of Texas at Arlington

This study will examine various instances of a technique I call the "Augmented 6th Medial Caesura," in which an augmented 6th chord immediately precedes the Subordinate Theme in a sonata exposition, rather than the expected dominant harmony. It will explore this form-defining gesture in 19th-century works by composers such as Tchaikovsky, Bruckner, and Dvorak, and explore its harmonic and tonal contexts, arguing that it blurs the boundary between transition and subordinate theme because of the harmonic progression that bridges the TR/ST border, rather than preceding it. Although the augmented 6th chord has been discussed in recent works by Lussier (2020) and Ellis (2010), this specific formal technique has not been previously examined.