Haydn's Missing Middles

Haydn's play on expectations and conventions and his deliberate grammatical mistakes are well-known. Yet one notable syntactic irregularity to be found in his music has been overlooked: the use of a sentential theme which lacks the first half of the continuation phrase (to use the terms of William E. Caplin's functional theory of Classical form). This type of theme moves straight from its presentation phrase to its cadential progression, so there is no pre-cadential section of the continuation phrase which expresses a specifically medial function. Moreover, the theme's dimensions are irregular: its second part is only half the length of its first. Most cases of the missing middle occur in the main themes of sonata allegros, the middle being supplied later in the movement, usually in the subordinate theme. These points are illustrated by brief analyses of the first movements of Symphony No. 85 and the Sonata Hob. XVI:21, and a longer analysis of the first movement of the Sonata Hob. XVI:49.