Aspects of musical rhetoric in Baroque organ music

The association between linguistic and musical principles was acknowledged by Baroque musicians
throughout the seventeenth and eighteenth centuries, a facet that attracted the attention of many musicologists
- mostly German (A. Schering, H. Brandes, and H. H. Unger)
- from the beginning of the twentieth century. This study presents an historical background to the whole concept of
musical rhetoric, beginning with Luther's theology of music, and focuses on the most significant theoretical compilations of the Baroque era that led to the
crystallization and final decline of musica poetica. Aspects of classical rhetoric are dealt with extensively, commencing with the rhetorical dispositio, as described by Greek and Roman authorities, followed by Mattheson's first
musical illustration of the (six-part) rhetorical structure
in vocal composition. The work focuses on the musical adaptation of two important elements of Baroque musica poetica. Musical-rhetorical figures are presented in chorale compositions by D. Buxtehude and J. S. Bach, conforming to the Baroque notion according to which composers were inclined to depict the allegory and symbolism of the theological text. The study proceeds to the demonstration of the rhetorical dispositio in free organ music, adopting a theory that explains the seemingly disjointed parts of the Klangrede ('sound-speech') notsimply as whimsical elements of the stylus phantasticus, but
rather as a scenario modelled on rhetorical thought. The alternation of passion and reason between the affective
(exordium and peroratio) and objective (narratio and
confirmatio) sections of the classical dispositio is demonstrated in specific pedaliter praeludia by D. Buxtehude, whose free organ works point to an advanced rhetorical plan hidden behind each composition.Buxtehude's musical-rhetorical dispositio is further applied to organ toccatas by N. Bruhns
(E minor) and J. S. Bach (BWV 551 and 566), whose rhetorical style, although different from that of Buxtehude, displays a sequence of contrasting sections also motivated by the functions identified in classical rhetoric.