Two tired but determined followers hasten after Jesus, praying for His help, pointing out that He tirelessly seeks to aid the sick and those who have strayed from the faith. Such is the text of the Duetto, the second movement of J.S. Bach’s cantata Jesu, der du meine Seele, BWV 78.¹

In Bach’s hands, it becomes the ground of a musical oration that is at once rich in affect, fresh in invention, and strong in structure. It opens a window into Bach’s musical world, the world of strong Lutheran faith and of a musical elite skilled in the art of musica poetica, that musical-oratorical art that flowered in German culture from at least the time of Orlando di Lasso’s stay in Munich in the late 16th century through the 17th and 18th centuries.² The Duetto is, to be sure, a simple da capo aria for two voices and continuo. But it is also a musical speech, meant to communicate the truth of the text and to teach the listeners the truth of Bach’s sturdy and plainspoken Lutheran faith. He seems to be saying that, if by chance the text itself is not clear enough, the lucky Leipzig listeners on the Fourteenth Sunday after Trinity in 1724³ will get the message by having the affections of their souls roused by the music itself.⁴

This short paper puts forth some preliminary observations about the dispositio (organization, Einrichtung) and the elocutio (the figural language, Figuren) of the Duetto. While it will not provide by any means an exhaustive study of the topics, if it helps performers to understand these from an 18th-century musica poetica perspective, it will have met its purpose.

Bach brings the traditions of rhetoric and oratory, faith, and reason together in his music.

Rhetoric and Oratory

He was the product of the Lateinschule tradition, with its roots in the classical tradition, and understood well how to use rhetoric as a pedagogical and motivational tool.

The rules of oratory and rhetoric provided a vocabulary of commonly understood gestures that composers used to "paint" the affects.⁵ The German practitioner of musica poetica took the text and fashioned the equivalent of it in sound, using musical devices and conventions appropriate to the affect of the text. The northern composer was not so much interested in display or operatic fireworks, or in dramatic effect for its own sake, but in the sober understanding of the text and its presentation in a musical setting that revealed the meaning and communicated the message. Good musical organization was a cornerstone of the practice. The dispositio was carefully considered, and the appropriate tonalities and figures, aspects of the elocutio, were then chosen.⁶

The dispositio of the speech is obviously the focal point of the [medieval] theory. From classical rhetoric, however, the theory overlapped into the epistolary genre and poetic composition, and acquired special significance in the art of preaching, in which it achieved a medieval perfection which was simultaneously intellectualist and Scholastic. Here it developed -- at the time, moreover, when polyphony was coming into general use -- in accordance with precise rules governing the theme and countertheme, their subdivisions, their development of countertheme, the return or the passage from one sentence to another. This is composition of incredible complexity, the theoretical simplicity and verbal virtuosity of which astonish us just as they were admired by medieval connoisseurs. The medieval sermon, the technical beauty (i.e., the embellishments or curiosities) of which was greatly admired by our ancestors, leads us into the esthetics of formal construction, as understood by the medieval writers, first of all in the literary arts, then in musical polyphony and architecture.⁷

Now the quotation above, from DeBruyne's Aesthetics of the Middle Ages, fits Bach's use of the art very well. From Boethius (480-524) onwards theorists embraced the Pythagorean ideal of music as a kind of speculative celestial mathematics. It was included among the subjects of the quadrivium, along with arithmetic, geometry, and astronomy, and so was taught by a member of the mathematics faculty. Practical music, applied music, performance, was considered as more of a craft that dealt with elocution and delivery, and so was aligned with rhetoric and oratory in the trivium, made up of grammar, dialectic, and rhetoric.⁸ So it was as an essential part of the curriculum that Bach learned rhetoric and oratory along with music. Musica poetica was an idea and practice of a piece with his education. Music was a speaking art, and a primary tool in teaching, especially the Protestant teaching of salvation by grace through faith.

Faith

When we venture to understand musica poetica as practiced by Bach, we encounter another great feat of integration, that of the world of Lutheran salvation by grace through faith with the rationalized figures of musica poetica. It is Bach's uncanny ability to balance these two divergent perspectives, to meld these great streams, that is at the root of his greatness. It is this consilience (the linking of facts and theory across disciplines) that is central to Bach, to 18th-century and Enlightenment thought, and, importantly for us, it also lies at the core of the phenomenon of musica poetica. (Bach was not the "backward-looking" traditionalist he is so often portrayed to be. He was a participant in his times, his times were changing rapidly and continuously, and he was certainly not immune to the zephyrs of the new.)

But before delving deeper into musica poetica proper, we will need to understand some Luther in order to see how the mid-18th century departed from the God-centered world-view. This will provide us with context so that we can begin to hear what the Duetto is saying to us, how it is attempting to persuade and edify us, how it tries to move our souls.

It is not important for the reader to have faith as Luther did, or to believe in the utter rationality of the world, as the 18th century tended to do. What is important is to enter willingly into these worlds for a while to see things as Bach might have, as his congregations might have, as his children and friends might have, the better to understand how his music works.

Tillich summarizes Luther's thesis for us: one is saved by grace through faith. This was Luther’s great, radical breakthrough against the Roman Catholicism in which he had been brought up, and in which he served.

The Catholic system is a system of objective, quantitative, and relative relations between God and man for the sake of providing eternal happiness for man. This is the basic structure: objective, not personal; quantitative, not qualitative; relative and condititioned, not absolute.¹²

Tillich summarizes Luther's pointed critique for us:

The relation to God is personal. It is an I-thou relationship, mediated not by anybody or anything, but only by accepting the message of acceptance, which is the content of the Bible. This is not an objective status in which one is; it is a personal relationship which Luther called "faith", not faith in something which one can believe, but acceptance of the fact that one is accepted. It is qualitative, not quantitative. Either a person is separated from God or he is not. There are no quantitative degrees of separation or non-separation. ...Likewise, it is unconditional and not conditioned, as it is in the Roman system. One is not a little bit nearer to God if one does more for the church, or against one’s body, but one is near to God completely and absolutely if one is united with him at all. And if not united, one is separated. The one state is unconditionally positive, the other unconditionally negative. The Reformation restated the unconditional categories of the Bible.¹³

Bach’s music always teaches. It is always teaching the lesson that one is saved by grace through faith - it is completely sufficient.

Reason

Reason is that function of consciousness through which we make sense of our world.

The Enlightenment, the Age of Reason (as it has been called) grew out of the work of Bacon, Locke, Hume, Winckelmann⁹, Lessing¹⁰ and others, permeated all Europe, and Bach was right in the middle of it. His life spans a time when the air was alive with new ideas alongside the old.

In contrast, the music around him in his maturity and of succeeding generations, was the product of a people who

increasingly came to consider that Christianity itself had been responsible for too many of the crimes of Western civilization, and that, rather than encouraging acceptable social behaviour, Christianity had simply fostered superstition, ignorance, and blind obedience to the rules and dogmas of the Church.¹⁴

Philosophy was being taught as secular religion, and the philosophes realized this, and felt keenly the competition, as Diderot wrote to Voltaire:

It is not enough to know more than they do, it must be shown that we are better than they are, and that philosophy can make more people good than grace.¹⁵

It is a key differentiator, a cleavage term: grace, the acceptance of being accepted. Grace: a term of salvation to Luther and Bach, a term of ignorance to the 18th-century philosophes, who wanted not to accept through belief, but who wanted simply to know. It is a difference of critical importance to performers of 18th-century music.

To Bach, music was a powerful didactic tool. Its melodic, harmonic, and formal gestures were codified in to a musical-rhetorical vocabulary that provided composers with the resources to communicate the affective content of the text. Instrumental music, too, used the same toolkit to create a "musical oration" capable of "speaking" in and of itself. The music thus became a "redende Kunst", a speaking art, and a bearer of carefully focused affect.

It is important to note in this connection that in saying that the music bears affect we do not imply that music must mean anything other than what it is, a fabric of tensional sonorous dynamic relationships. It is, however, in and through this play of dynamic energies that figures and gestures by their very physiognomy embody and evoke affect. We will point this uncanny capacity of music through a number of examples in the course of this paper, and will hope, through description and association, to point to the subtle mechanism through which the music communicates, in Bach’s hands, the Christian message, while not in and of itself bearing any conceptual meaning outside of itself as dynamic play.¹⁶

The specific bearers of the Affekten can be any musical element, such as key, tempo, rhythm, or, especially for our Duetto, melodic figures. These figures had been variously defined over the years in treatise after treatise, whose authors included such distinguished musicians as Johann Mattheson, Walther, Vogt, and Spiess. These figures are of signal importance, because they formed the gestural vocabulary of the musical style. The tradition of the musical-rhetorical Figuren was so strong, in fact, that these motives, these temporal gestures, these melodic shapes were carried over into succeeding generations, and key stylistic elements in music of the rococo, galant, empfindsamer, and even the mature classical style, especially in the operas of Mozart, where they manifest as dramatic gestures central to Mozart’s musical style and affective vocabulary.¹⁷ Writers such as Forkel, Marpurg, Kirnberger, and Koch wrote on the importance and significance of musical rhetoric, with Forkel even claiming that it was only in his time (the 1780s) that the musical style had matured enough to make a true musical rhetoric possible.¹⁸

I venture to say that to understand music before 1800 properly, one must account for the use of the devices of musica poetica and understand how these are used both structurally and with affective intent, to characterize the Affekt implied or overtly stated in the text, and to communicate the message of the text to the listeners in subtle, direct, immediate ways available only to music. Bach was, after all, probably the greatest exponent of Protestant (Lutheran) thought and doctrine after Martin Luther himself, and he is always teaching us something in his music.¹⁹

If we come to listen to Bach’s music afresh, and hear it on its own terms, as it is in itself, we can encounter the raw reality of Bach’s teaching. Performers of this music owe it to themselves and to their listeners to educate themselves in the ways of musica poetica, and become at ease with its baroque mechanisms. Every performance should be a meeting of the music and the mind of the listener, an encounter at the boundary of each, so that each may inform the other, and both benefit, the music by being understood and appreciated, and the mind shaped, formed, and energized by the astonishing power and subtlety of Bach’s art.

Dispositio: Organization and Form

If you are going to make a speech, the first thing you must do is to decide what you will talk about: you must choose the subject matter, the theme. This was known as the inventio, and the orator relied on the loci topici, or the likely topics for elaboration.

The topic text (Ex. 1) for this movement is the believers beseeching Lord Jesus for help while trying as hard as they can to reach Him, hastening with faltering, feeble, though eager footsteps along the path. We as humans admit that we fail with each step in life, yet we know that You seek out the sick and those who have strayed , as we regularly do, and we ask that you look upon us mercifully and grant us salvation through your Grace.²⁰

Once the topic was chosen, the musical orator had to structure the presentation such that the message be clearly stated, supported with illustration and example, that contrary points of view be introduced and confuted, and the argument restated in summary. Such was the essence of the dispositio, the next area of concern for the musicus poeticus.

The dispositio has six sections:

The composer thought as an orator would, and organized the musical elements as the speaker would words and concepts. There must be an opening or introduction, a statement of the main theme, or the laying out of the facts, a clear statement of the point to be made, supporting arguments, rebuttals of differing or contrary points of view, and an affirmation in the close, or concluding comments. For the German composer especially, orderly construction and figural eloquence were favored over dramatic delivery, theatrics, and display.²¹

If we ignore musica poetica for the moment and analyse the form in purely musical-material terms, the Duetto is a da capo aria, with the first section a ternary form in the key of B-flat, with a movement to the dominant F in mm. 16-30, and a reestablishment of the tonic thereafter. The second section moves to g-minor, and throughout its 47 measures it features the shifting, sometimes inchoate harmonic vocabulary typical of the form. The third section is a literal repeat of the first section.

But the Duetto demands that we hear it as a musical oration. It follows the classical recipe of the dispositio: exordium, narratio, propositio, confirmatio, confutatio, and peroratio. The first section has an exordium of 8 measures, which exposes the material that will be worked with and elaborated. This is followed by a narratio, also of 8 measures, which is the first statement of the canonic vocal theme above a repetition of the exordium in the continuo. The propositio stretches for 14 measures, elaborating on the material stated in the exordium and narratio. The confirmatio, starting in m. 30, restates the opening material, and reinforces its message through repetition. The peroratio (mm. 37-50) brings the section to a close by summarizing the thematic material with a succinct restatement.

The Aria Duetto is also formally a da capo aria, with the first section a ternary form in the key of B-flat, with a movement to the dominant F in mm. 16-30, and a re-establishment of the tonic thereafter. The B section moves to the relative minor on G, and is characterized by unstable, shifting tonality, and by the introduction of contrasting musical material. It is a true confutatio section, where the contrasting musical "arguments" are dealt with and, with the reestablishment of the dominant of the home key of B-flat, successfully rebutted.The third section is a literal repeat of the first: it constitutes an extended peroratio, for it reestablishes the main thematic material and brings the movement to a close.²²