It is a commonplace observation that at many points in the history of tonal music, contemporaneous theorists have been hard pressed to keep pace with the more progressive efforts of imaginative composers. This phenomenon is particularly noticeable in theoretical writing of the late eighteenth and early nineteenth centuries, in which theorists were faced with the task of explaining an expanding vocabulary of chromatic operations which could not be rationalized satisfactorily from the existing foundation of theoretical concepts. In fact, as Matthew Brown observes in his recent article in the Journal of Music Theory, some modern speculative theorists have been forced to divide the so-called period of common practice into, on the one hand, "classical diatonic tonality" with one set of rules and assumptions and, on the other, "nineteenth-century chromatic tonality," in which fundamentally new assumptions must be made.1
The following is an attempt to come to a greater understanding of this divergence in harmonic practice by examining the use of certain harmonic procedures in the music of Joseph Haydn, whose later works stand near the intersection of these two epochs, and by considering the efforts of theorists of the late eighteenth century to rationalize Haydn's progressive harmonic language.
Haydn's uses of third-related keys, especially as they occur in or among the movements of a multi-movement work, cannot easily be explained using eighteenth-century conceptions of key relation. The inadequacy of existing theory is graphically illustrated in August Kollmann's Essay on Practical Musical Composition,2 in which the author attempts unsuccessfully to rationalize certain key relationships among the movements of Haydn's piano trios Hob.XV:27-29.
It is possible, however, by examining the evolution of Haydn's approach to the use of third-related keys to speculate on a rationale the composer himself may have had in mind in the use of these key relationships. Obviously there are dangers in this line of approach: Haydn was not a theorist and he did not feel compelled to articulate any specific theoretical system either in writing or in conversations with his early biographers. Although the composer's ultimate intentions can only be a matter of speculation, the body of music from which this concept of harmonic relations can be inferred is substantial and the evolution of Haydn's methods can be traced clearly.
This paper considers the issue of Haydn's third-related keys in three ways: first, by examining briefly the writings of certain late eighteenth-century theorists; second, by proposing a new theory that is suggested by Haydn's actual practice; and finally, by tracing the evolution of this system in Haydn's later instrumental works.
In his recent article, "The New Modulation of the 1770's: C. P. E. Bach in Theory, Criticism, and Practice," Richard Kramer sheds new light on a revised edition of Bach's Versuch über die wahre Art das Clavier zu spielen that was published in 1797 by Engelhardt Schwickert.3 In a supplement that was added by Bach to the last chapter of his treatise the subject of modulation to distant keys is discussed and examples from certain works of Bach-identified for the first time in modern writing by Kramer-are given as illustrations. In the course of his discussion of a Rondo in C major (which Kramer identifies from the collection Ciavier-Sonaten nebst einigen Rondos für Kenner und Liebhaber. . . W.56), Bach offers a rationale for modulations to keys that are not closely related: 4
When I played this rondo, I was asked . . . "Who but yourself would dare go directly from C major to E major?" I replied, "Anyone can and will assuredly do it who knows that E is the dominant of A, and that A minor is very closely related to C major."
This rationale for distant key relations is common among theorists of the second half of the eighteenth century. For example, in Die Kunst des reinen Satzes in der Musik (1771-1779), Johann Philipp Kirnberger writes that when it is "occasionally . …