Expecting the Unexpected: Haydn’s Three-Part Expositions

In 1929, Sir Donald Francis Tovey, a British music critic and theorist, described the unusual nature of Op. 20, no. 2, in C major, an early string quartet written by Joseph Haydn: This description features Tovey’s first analytical use of the term “purple patch.” In his formulation, a purple patch was a modulation to an unexpected harmonic area—a practice that became commonplace in the early Romantic period, especially in the music of Ludwig van Beethoven and Franz Schubert. But Tovey described this concept in string quartets by Joseph Haydn, predating the Romantic era in some cases by fifty years. The fact that Tovey first applied the purple patch to music written by Haydn—not Schubert or Beethoven—inspired the current investigation of the connection between Tovey’s purple patches and Haydn’s string quartets. The longstanding affiliation of the color purple with emperors and the aristocracy alike stems from its extremely rare and expensive dye. The color, however, has connotations besides those of its royal origins: the phrase “purple prose,” which refers to an elaborate or florid literary passage that stands apart from its surrounding material, seems to have inspired Tovey. He appropriated this meaning in order to illustrate the way in which the inherently rigid and polarized tonal system of the Classical style marginalized digressions to an unusual key. These digressions stand apart from the twin poles of the tonic and the dominant, thereby earning Tovey’s designation as “purple patches.” By extending Tovey’s analytical model to all of Haydn’s string quartets, I have uncovered three compelling facts: 1) an unusual structure, unlike the majority of works written in the Classical period, appears in twenty five of Haydn’s quartets; 2) an harmonic digression, described by Tovey as a “purple patch,” appears in sixteen of these quartets; and 3) these unusual works, which are known as “three-part expositions,” are propelled the dynamic harmonies of the purple patch, a function that heretofore has gone unnoticed in the scholarly literature. The general structure under consideration here is known as “sonata form.” It appears in a majority of the compositions written during the Classical period (c.1750–1810), and Joseph Haydn was one of the earliest Classical composers to utilize it. Despite its predominance at the time, a “typical” sonata form was not codified until later in the nineteenth century under the next generation of composers and theorists. During the time of Haydn’s compositional practice, however, sonata form existed in many different variations. The most prominent one is known as the “two-part” exposition, whereas “monothematic” and “three-part” expositions were more rare. In fact, the latter structure seems to be restricted to Haydn’s oeuvre, rarely appearing in the works of Beethoven and never in Mozart. According to James Hepokoski and Warren Darcy, “the two-part exposition was by far the most normative model of the late eighteenth century.” Given the disparity in the rate of appearance between the two- and three-part expositions, it is safe to assume that a typical listener in the late eighteenth century might expect to hear a two-part exposition at any particular performance. This presents us with an opportunity: if one were to provide such a typical listener with a three-part exposition, in lieu of the expected two-part form, what might result? In other words, why might a composer of Haydn’s stature use such a strategy? The main concern of this paper, therefore, is an investigation of what differentiates the three-part exposition (i.e., the atypical form) from the two-part exposition. In the triumvirate of major Classical composers, Haydn antedates Mozart’s birth by twenty-four years and Beethoven’s by thirty-eight. His role as the father of the string quartet …