The church tones, or tuoni ecclesiastici, are a set of tonalities arising from the harmonization and transposition of the eight Gregorian psalm tones in Roman Catholic Offices. Adriano Banchieri's classic theoretical presentation of the church tones in L'Organo suonarino (1605) was followed by a long succession of treatments by other music theorists, not least of all Johann Mattheson, who in Das neu-eröffnete Orchestre (1713) used them as the foundation for his first listing of the twenty-four major and minor keys. This dissertation traces the church tones from their origins in late-sixteenth-century Italian psalmody, through Austrian and Bavarian sources, to their reception in the eighteenth century by north German theorists.
Because the church tones arose from the complex interaction of various conventions and practical constraints, not all Baroque musicians recognized them as modal categories in their own right. Others did recognize them as such, however, regarding them as the "tones according to the modern use" or as a reduction of Zarlino's twelve modes, and presenting them using the same theoretical apparatus used to explain the traditional eight- and humanistic twelve-mode systems. Changes in modal representation in a large body of keyboard cycles ordered according to the church tones suggest that the "transition from modes to keys," while incremental in certain respects, is best explained in terms of paradigm shifts occurring around the beginning and ending of the Baroque rather than as an evolutionary process. By mediating between vocal and instrumental ways of organizing tonal space, the church tones bridged the vocally oriented, twelve-mode system of the sixteenth century and the keyboard-oriented, two-mode system of the eighteenth century.