The study of rhetoric dates as far back as Antiquity, but the significance of this tradition was almost completely forgotten by the beginning of the twentieth century. Commonly defined as the ‘art of persuasion’, investigation of rhetoric’s role in organising thought – through music as well as text – has recently undergone something of a revival.
The origins and significance of rhetoric in Antiquity can be seen in poetry of the period. Modern scholar Hugh Tancred-Lawson has pointed out that Homer’s Iliad gives great importance not only to the theme of military prowess, but also to competency of self-expression; one of the main plot elements centres on the need to rouse Achilles into action through persuasion. In Ancient Greek society, persuasive articulation of one’s ideas in debate was second only to conquest on the battlefield.
Rhetoric continued to play a significant role in education throughout the medieval period. Medieval students were to acquaint themselves with ‘the classics’, seeking knowledge through the study of figures of speech and other rhetorical elements in this growing body of literature. More than this, however, the study of rhetoric was also the principle means by which the ‘medieval mind’ learned to arrange the world into an eloquent, comprehensible order. 
Analogies between music and the spoken arts also have a long history, and musical concepts of rhetoric date back as far as the ancient world, particularly to the writings of Aristotle, Cicero and Quintilian. Classical rhetoric comprised five elements: inventio (finding an argument); dispositio (ordering the argument); elocutio (style); memoria (memory); and pronuntiatio (delivery), which served the purposes of moving (movere), delighting (delectare) and instructing (docere) audiences. By the end of the fifteenth century these concepts had permeated the writings of music theorists, and the music of composers such as Josquin des Prez (c.1450/1455–1521).
New attitudes toward the relationship between words and music encouraged great aesthetic changes at the turn of the seventeenth century, ushering in what we now call the baroque period. Composers such as Giulio Caccini (1551–1618) published collections of arias in a self-consciously ‘new’ monodic style, whose stark distinction between melody and bass cleared a path for new investigations into the relationship between musical and poetic forms. Music had, like never before, become the servant of words, and composers committed themselves to exploring music’s potential for enhancing the emotional and affective content of their texts.
Rhetoric in arias
Without doubt, the most important musical genre for arousing the passions of audiences in the baroque period was the aria. Pier Francesco Tosi’s highly influential treatise on singing, Opinioni de’ cantori antichi, e moderni, o sieno osservazioni sopra il canto figurato (Observations on the Florid Song), which is structured as an instruction manual for teachers, emphasises the need for student training in composition, singing and the application of ornaments, as well as grammar, diction, social decorum and acting. In the chapter on singing arias, Tosi counts ease and naturalness as among the most important aspects of delivery in performance, with the aim of achieving the much-lauded cantabile style. He writes (following John Galliard’s English translation (1743)),
The most necessary Study for singing Airs in Perfection, and what is more difficult than any other, is to seek for what is easy and natural, as well as of beautiful Inventions. One who has the good Fortune to unite such two rare Talents, with an agreeable putting forth of the Voice, is a very happy Singer. 
Rhetoric in recitatives
Conventions governing the performance of recitatives in the seventeenth and eighteenth century are much more difficult to establish with any sense of certainty, since very little was captured by the music notation. Many elements were left up to the discretion of performers. In contrast to the singing of arias, however, the speech-like style of singing characteristic of recitatives can be understood through the lens of contemporary literature on declamation, which provides a practical model for recitative delivery.
Rhetorical precepts concerning declamation, especially in the context of theatrical performance, were set out in numerous publications, most notably by Leone de’ Sommi (1567) , Andrea Perrucci (1699) , and Luigi Riccoboni (1728) .
These authors lead us away from the idea of ‘singing’ recitative, toward a delivery more closely aligned with the heightened speech of an orator, filling in many of the expressive features absent from the musical notation. Giambattista Mancini elaborated on this link between declamation and recitative performance in his 1777 publication Riflessioni pratiche sul canto figurato, where he writes:
Listen to the speech of a good orator, and hear how many rests, what variety of tones, how many different emphases he uses to express its meanings. Now he raises his voice, now he lowers it; now he hurries a bit, now he grows harsh and now gentle, according to the various passions that he wishes to stir in the listener… There are some who beat and batter the recitatives because they will not take the trouble to learn the rules of perfect declamation. 
Recitative can thus be read not as music, but as ‘musically elaborated declamation’; a combination of written notes on the page with the rhetorical principles guiding their rises and falls, their stresses and their variations in rhythm, timbre and articulation.
The importance of gesture in rhetorical delivery was also emphasised by Cypriano Soárez in his 1569 publication De arte rhetorica (On the Art of Rhetoric), which remained highly influential in Jesuit schools throughout the seventeenth and eighteenth centuries. He writes,
It is agreed that all action is contained in two categories: the sound of the voice and the movement of the body… In fact these alone move an audience to the greatest degree, because at the same time the voice has impressed their ears, gestures their eyes, and words their thoughts… 
The anonymous author of Il corago, a famous treatise on staging and directing written in the 1620s or 1630s, also highlighted the significance of gesture in rhetorical delivery:
The manner of reciting is of great importance, because something said by a person who knows how to deliver it well and accompany it with gesture will make a much greater impression on the spirits of the listeners and will more easily stir in them the affections of anger, of hatred, of passion, of happiness, and the like. This will not happen when it is simply narrated by someone without gesture or modulation of the voice. 
Gesture thus played a crucial role in stirring the passions of audiences in the baroque period, and performers of seventeenth- and eighteenth-century music can enrich their interpretative approaches to this repertoire by investigating these conventions.
John Bulwer’s Chirologia, or the Naturall Language of the Hand… (1644) provides fascinating insights into the ways particular hand and arm movements could communicate emotional and affective stances at this time. He writes, for example, ‘both hands clasped and wrung together is an Action convenient to manifest griefe and sorrow’. 
Rhetorical figures in music
Composers too, especially those working in German-speaking lands, contributed to the development of a large body of musical-rhetorical figures, or Figurae. Each of these referred in some way to an aspect of human emotional experience, although this was by no means a unified practice.
Scholar Dietrich Bartel has investigated this tradition in great detail , and many of these rhetorical figures will be well known to lovers of baroque music, if not by name. The passus duriusculus, for example, most often manifested as a descending chromatic line covering the interval of a fourth, and was commonly associated with sorrow and lamenting. It can be heard in the bass line of one of the best-known arias of the seventeenth century, ‘Dido’s Lament’, from Henry Purcell’s Dido and Aeneas (first performed in 1689).
While the German musica poetica tradition theorised musical rhetoric by analogy with verbal rhetoric as a way of analysing how music could be structured and made expressive, it was only when rhetoric was put into practice in performance, through dramatic vocal inflection, improvised embellishment and eloquent gesture, that it conveyed all of its emotional power to audiences, drawing them into a powerful affective experience.
The ultimate purpose of rhetoric as a discipline was to systematise the skills of persuasion which came naturally to some people, but by developing a method, they could be learnt by others. It is with the historical knowledge of rhetoric in mind that the forthcoming production of Voyage to the Moon is such an exciting enterprise: we can explore how historical emotions of the eighteenth century were thought, felt and expressed.
While we do not use the same system of training today, the fundamental skills of musical and dramatic communication remain embedded in human cultures and continue to be basic to the work of skilled creators and performers in synthesising old and new materials into a powerful theatrical experience. We can explore how the audience is ‘moved’ by twenty-first century rhetorical devices employed by both the creative and performance teams.
By the Voyage to the Moon researchers Jane Davidson, Joe Browning and Frederic Kiernan, based at the University of Melbourne. Jane Davidson is Professor of Creative and Performing Arts (Music) at the Faculty of the Victorian College of the Arts and Melbourne Conservatorium of Music, The University of Melbourne, and Deputy Director of the Australian Research Council’s Centre of Excellence for the History of Emotions (CHE). Joseph Browning is a ethnomusicologist and postdoctoral research fellow at CHE specialising in the shakuhachi, central Javanese gamelan, and ethnographic approaches to Western art music. Frederic Kiernan is a PhD candidate at the Melbourne Conservatorium of Music and research assistant at CHE.
1. Ernst Robert Curtius, European Literature and the Latin Middle Ages, trans. Willard R. Trask (Princeton: Princeton University Press, 2013), pp. 64–68.
2. Pier Francesco Tosi, Opinioni de’ cantori antichi, e moderni, o sieno osservazioni sopra il canto figurato, trans. John Galliard (London, 1743), p.97.
3. Leone de’ Sommi, Quattro dialoghi in materia di rappresentazioni sceniche: a cura di Ferrucio Marotti (Milan: Edizioni il Polifilo, 1968).
4. Andrea Perrucci, A Treatise on Acting, From Memory and by Improvisation: Dell’arte rappresentativa, premeditata ed all’improviso, trans. and ed. Grancesco Cotticelli, Anne Goodrich Heck and Thomas F. Heck (Lanham, MD: Scarecrow Press, 2008).
5. Luigi Riccoboni, Dell’arte rappresentativa: Capitoli sei (London, n.p.: 1728).
6. Giambattista Mancini, ‘From Practical Reflections on Singing’, trans. W. J. Allanbrook, in Leo Treitler, ed., Strunk’s Source Readings in Music History, rev. ed. (New York: Norton, 1998), p. 871.
7. Cipriano Soárez, S.J., De Arte Rhetorica Libri Tres ex Aristotele, Cicerone et Quintiliano Praecipue Deprompti (1722; repr. Delhi: Gyan Books, 2013), 187–90. Translation by Adam Harris.
8. Leo Treitler and Margaret Murata, eds. ‘From The Choragus, or, Some Observations for Staging Dramatic Works Well’, in Strunck’s Source Readings in Music History Vol. 4: The Baroque Era (New York: Norton Publishing, 1998), 633.
9. John Bulwer, Chirologia, or the Naturall Language of the Hand… (London, 1644), p. 55.
10. Dietrich Bartel, Musica Poetica: Musical-Rhetorical Figures in German Baroque Music (Lincoln and London: University of Nebraska Press, 1997).