When we invoke the notion of form-functional fusion (Caplin 1998), we are describing a situation in which two formal functions are heard within the same unit of a form. Sentence themes, for example, often fuse the continuation and cadential functions at the theme’s end. In these cases, the forward drive of the continuation is a fitting partner for the cadential function as the two accelerate towards the theme’s final chord, or cadential arrival. In other types of fusions, however, the functions are often at odds with one another and blended asymmetrically with one taking precedence over the other. As Caplin (1998, 111) contends,
if a given function is actually placed differently from its expressed temporal position—if a medial function appears as a beginning, for example—a kind of formal “dissonance” will result. If that dissonance is carefully controlled, it may be suitable for expressing a loose organization.
Despite the literature’s neglect of these dissonant fusions, as they may be called, they remain an important compositional principle in classical works since they are often found in the theme areas of a form. This paper will therefore investigate the subject by establishing several categories of dissonant fusions in themes by Haydn, Mozart, and Beethoven, and demonstrating how the prevailing function of each passage is loosened.