Both James Hepokoski and Warren Darcy’s Sonata Theory and William Caplin’s theory of formal functions give prominent place to sonata expositions that lack, in any traditional sense, an obvious subordinate theme—Hepokoski and Darcy through their category of the “continuous exposition” and Caplin through his notion of “transition/subordinate theme fusion.” Such expositions are a prominent feature of Haydn’s compositional practice, and have long been discussed by specialists writing on his music. In particular, in his 1963 essay “Sonataform-Probleme,” Jens Peter Larsen held up Haydn’s “three-part expositions” as an alternative to the standard, A. B. Marx-derived “two-part” model. Following Alexander Ludwig’s lead, my paper revisits Larsen’s original formulation in an attempt to illuminate its relationship to Caplin’s and Hepokoski and Darcy’s conceptions. The analytical examples are drawn from Haydn’s Piano Sonata in C minor, Hob. XVI:20 and his String Quartets, Op. 33, no. 1 and Op. 74, no. 3.