Vivaldi research describes his harmonic-tonal language as uniformly forward-looking and advanced, in line with other innovatory characteristics of his style. Nevertheless, an analysis of Vivaldi's tonal structures suggests that the basic parameters of harmonic tonality are not relevant to understanding his tonal processing. A discussion of his harmonic language requires special terms, capable of expressing the intricate process of the establishment of the tonal system.
In the dissertation Vivaldi's tonal and harmonic thinking is discussed through an examination of the large corpus of opening movements from 442 of his concertos. The discussion concentrates on the principal parameters of Vivaldi's harmonic language, primarily responsible for the long-range organization of tonal space in concerto fast movements. The principal conclusion is that in Vivaldi's harmonic idiolect a persistence of modal thinking is closely interwoven with elements of a modern, still uncertain, concept of major-minor tonality.
The intricacy of Vivaldi's harmonic concept would be properly understood only as part of the musical-theoretical tradition out of which it emerged. At the same time, Vivaldi's important contribution to the language of harmony, to the establishment of tonality and to the formation of the tonal-harmonic grounds of instrumental composition spurred the development of musical practice and theory.
The treatment of key and tonality in Vivaldi's concertos offers striking parallels to some specific statements found in important German treatises, such as Der General-Bass in der Composition (1728) by Heinichen, Das neu-eröffnete Orchestre (1713) by Mattheson and Grundregeln zur Tonordnung insgemein (1755) by Riepel. Clearly, then, despite the long period of oblivion into which Vivaldi's music fell, it did have a decisive impact on both theoretical writings and practical activity during his own time and on posterity.