Changing metre

In the eighteenth century the constancy of notated metre was taken for granted by both composers and listeners. Virtually every piece or movement was written with one time signature from the beginning to the end. Exceptions to this rule occur in movements preceded by a slow introduction, which normally differs from the following main part of a movement not only as regards tempo but metre as well. However, within the same notated metre, the composed metre could change. One class of changes consisted in varying the period or phase of a composed metre. The former could be caused by imbroglio and hemiolas, the latter by syncopations. In contemporaneous music theory such metric changes were described as ‘confusions’ (Verwirrungen) by Joseph Riepel and ‘shifts’ (Rückungen) by Heinrich Christoph Koch. Because they referred to the mechanism of metric perception, they were accessible to all attentive listeners including less cultivated ones (Liebhaber). Another class of eighteenth-century metric manipulations relied upon the theoretical knowledge of the listener and hence could be appreciated only by Kenner able to properly interpret cues provided by the composer. Such manipulations involve a change of the level of the metrical hierarchy corresponding with the so-called ‘parts of the measure’ (Taktteile).

The most important cues used by eighteenth-century composers to indicate the metrical level of Taktteile are ending formulas represented by Einschnitte, Absätze and Kadenze. As repeatedly emphasized by authors of composition handbooks, caesura notes of these formulas must fall on a strong Taktteil (downbeat).

In view of the diverse approaches to musical scholarship current today, the position that music's function is communication is not an obvious one to take. For many, a musical piece is an object to be contemplated, an organism to be examined, a mechanism to be deconstructed or a product to be consumed. None of these metaphors allows one to speak sensibly of musical communication. Yet none of them was in use in the late eighteenth century. At that time theoretical and aesthetic discourses about music were based upon the metaphor of music as language. Within this metaphor, a composer or performer was compared to an orator, and a musical piece to an oration subdivided into parts, periods and sentences. Just as the art of rhetoric had its raison d'être in persuading the listener, so the art of composition consisted in arousing his sentiments. The musical repertory labelled by later generations as the ‘Classical style’ was thus an expression of the aesthetic stance which conceived of music as communication between composer and listener.

And yet, the comparison with rhetoric, dating back to the beginning of the sixteenth century, does not fully explain the characteristics of musical communication in the late eighteenth century. Rather, these characteristics are related to transformations of musical life bearing fruit in this period. Little by little, from the early decades of the eighteenth century on, music becomes the favourite kind of entertainment for the middle classes.