Kelvin H. F. Lee

This article revisits the long-standing issue of form in the Adagio of Mahler’s Tenth Symphony (1910) in light of recent developments in Formenlehre and neo-Riemannian theory. I consider the movement’s sonata properties, as discerned by Kofi Agawu (1986) and Richard Kaplan (2005), by exploring the applicability of William E. Caplin’s form-functional theory (1998) and James Hepokoski and Warren Darcy’s Sonata Theory (2006) in a post-Wagnerian tonal environment, construed in terms of Richard Cohn’s hexatonic systems (1999) and Julian Horton’s model of orbital tonality (2018). While the argument posits a hexatonically orientated conception of form based on what I theorise as hexatonic tension, special attention is given to the idea of breakthrough as an analytical and hermeneutic point of reorientation: conceived after Janet Schmalfeldt’s concept of becoming (2011), the breakthrough initiates a retrospective reinterpretation of the Adagio’s tonal universe and consequently turns its form into a diatonically orientated sonata form. The article thus explicates the formal function of breakthrough based on Theodor W. Adorno’s aesthetic formulation, propounding a chromatically inflected model of sonata form in response to Seth Monahan’s call for a novel framework for Mahler’s late works (2011). Together they constitute a foundation of a theory of fin-de-siècle modernist symphonic sonata form.