In May 1747 Johann Sebastian Bach (1685-1750) was 62 years old. In three years he would be dead, closing one of the most significant chapters in music history. The breadth and technical mastery of Bach’s output is unparalleled, though he never achieved the international fame during his lifetime that posterity would gradually accord to him. For instance, the complete catalog of his works produced posthumously under his son’s guidance, the far-reaching Baroque revival inspired by Felix Mendelssohn in the mid 19th century, the virtuoso transcriptions of Bach’s works for all kinds of instruments and ensembles, the global name recognition – all this could not have been foreseen when the aged Kapellmeister rumbled down the royal road outside Potsdam, heading for an historic meeting with Frederick the Great at the Prussian King’s summer palace, Sanssouci.

Frederick was deeply fond of music and, as we will see, had musical aspirations and talents of his own. Those interests didn’t always sit well with his militaristic father. Young Frederick’s life included many confrontations between father and son, and it was only after several drastic, debilitating actions that Frederick acquiesced to parental control over his future. He was sent to military school for formal training, but he never left music behind. Evening concerts, with Frederick himself playing flute, were a regular feature of life at court. Upon ascending to the throne in 1740 and establishing his alternate residence at Sanssouci, Frederick retained most of his favorite musicians, including his long-time flute teacher Johann Joachim Quantz (1697-1773).

Born in a small town near Göttingen in central Germany, Quantz was destined to follow his father into the blacksmith trade until the latter’s death offered Joachim additional options. He seized a chance to study music with various relatives, and already by his early teens had settled on a career in music. He had the good fortune to secure a position at the Dresden court in 1716, bringing him into direct connection with several significant musical figures like Jan Zelenka and flute virtuoso Pierre Buffardin. Finishing touches were applied during a traditional “grand tour” of Europe’s musical capitals from 1724 to 1727. Quantz first met Frederick when the tour ended, and the two forged an immediate connection. However, Quantz’s Saxon employer would not release him to join Frederick’s retinue. Thus it was not until 1741, a year after Frederick ascended to the Prussian throne, that Quantz arrived in Berlin to regale king and court with modern flute music. In addition, Quantz was an expert flute builder who made key developments in flute construction and technique, culminating in A Treatise on Flute Playing (1752).

Quantz’s Trio Sonata in A Minor (ca. 1740) typifies one of the most fundamental forms of the Baroque era. Scored for two treble instruments plus harmonic support from the continuo, Trio Sonatas were eminently flexible. Movements could be added or removed depending on the situation. Leading lines could be played on a number of treble instruments (flutes, oboes, violins and violas, or even trumpet for particularly festive occasions). In today’s performance Quantz’s Sonata is performed by two oboes and transposed down to G minor, a key better suited to the oboe’s range. Four movements alternate between slow and fast tempos, as was conventional in the sonata da chiesa (church sonata). Structurally, all four feature canonic imitation between the two solo lines. What changes from one movement to the next is tempo and general affect, as well as tonalities centered around G minor and B-flat major. The opening Andante moderato moves at a gentle pace, ending with an open cadence that leads directly to the ensuing Allegro. The third movement, a simple and restrained Affetuoso, provides brief respite before a spirited Vivace. As mentioned, such works are staples of Baroque chamber music. Quantz literally wrote dozens of Trio Sonatas, though only a handful survive; still fewer are heard live in performance.

At court, Frederick also hired J. S. Bach’s son, Carl Philipp Emanuel. It was through this connection that Sebastian Bach received an invitation to Sanssouci in 1747. The King was certainly not enamored of the old master’s brand of intellectually difficult music. However, young Emanuel Bach had just become a father, and the sympathetic monarch thought the timing fortuitous to bring father and son together. Also, Frederick had just received a shipment of new fortepianos, and he wanted Old Bach’s assessment of these novelties. Thus, almost immediately upon his arrival, Bach was summoned to the King’s music rooms to test the new fortepianos. By all accounts he dazzled the attendees, including the King, with his improvisations at each keyboard. His reputation clearly preceded him. Frederick was armed and ready with a fugue subject meant to stump the master. Bach, of course, was not to be put off and exceeded all expectations when he improvised fugues on this “royal theme.” Bach subsequently completed and published a series of movements based on the melody, producing The Musical Offering (Das Musikalische Opfer). It’s a charming story but probably not entirely accurate. Let’s summarize what we know.

First, consider the thema regium or “king’s theme,” supposedly provided by Frederick out of his own head. The opening half of the theme (C-minor triad plus a falling dissonant leap) is not uncommon as a fugue subject. But the tail end, with its chain of chromatic half steps sliding in and out of the home key, offers a greater challenge. Indeed, the subject uses eleven of the twelve tones in the Western musical octave – a level of complexity and tonal richness that would eventually cause the transformation of tonal music as Bach would have understood it. Tradition ascribes this tune to Frederick himself; there is some doubt about that (“could a talented amateur invent such a probing chromatic theme”?), but it is certainly not out of the question. One scholar has pointed out that a movement from Quantz’s own Trio Sonata in C Minor (1741) begins with the same rising triad and falling diminished 7th.

By all accounts, Bach rose to the occasion at Sanssouci by improvising a three-voice ricercar on the spot. Whether Bach also performed his six-voice ricercar immediately thereafter or the next day is unclear, but he did ask for time to work out the piece to perfection. He returned home to Leipzig to work out the details. Two months later Bach sent Frederick a specially dedicated copy, by which point he had added a Trio Sonata and riddle canons. A canon is essentially a leading voice followed by an answering voice that enters with the same melody after a certain time interval. The examples in The Musical Offering are called “riddle canons” because Bach has left it up to the players to figure out when the following voice should begin. Furthermore, almost every imaginable permutation of the canon material is presented: playing the royal theme backward against itself, playing it upside down, upside down andbackward, in slower and faster rhythms, in different keys like a fugue – it’s all there. If a canon is the musical equivalent of “follow the leader,” these canons are something akin to playing Twister blindfolded.

About a decade before Sebastian Bach visited Sanssouci, Prince Frederick selected one of Bach’s sons to join his retinue in 1738. That placed 24-year-old Carl Philipp Emanuel Bach(1714-1788) alongside some of the most respected men in European culture. Of course, it is not surprising to find Emanuel Bach in such a prestigious post. He prospered quickly in his musical activities. Two years later Frederick became Prussia’s King and moved to Berlin, where Emanuel continued as principal harpsichordist. At this time he began composing influential sonatas for solo keyboard, pieces that were often highly experimental in both form and content. Emanuel Bach developed a lasting reputation for the bravery and idiosyncratic nature of his use of dissonance, chromaticism, and mercurial changes of key.

By the early 1750s C. P. E. Bach was also gathering aesthetic and technical observations into a treatise. The Essay on the True Art of Playing Keyboard Instruments is far more than a guide to the proper rendition of ornaments or how to realize composer’s tempo indications. It addresses fundamental notions of harmonic progressions, improvisation, expressivity through tone, and strategies for tastefully accompanying from figured bass lines. This last area was one in which Emanuel Bach had proven his mettle firsthand. Early in his tenure at Berlin, he was given the perilous honor of accompanying Frederick during the monarch’s own flute performances. Emanuel fulfilled his royal task admirably and was clearly productive in many other areas of activity.

Long ascribed to J. S. Bach, the Sonata in G Minor, BWV 1030, is almost certainly by C. P. E. Bach. Best known in a setting for flute and harpsichord, the version for oboe may in fact represent its original form. In either case, this sonata represents a trend that grew increasingly influential over the 18th century: the sonata for solo instrument and obbligato keyboard. Before C. P. E. Bach’s time, most sonatas for a single instrument were accompanied by the basso continuo. In writing out a part for the keyboard and giving the player’s right hand an equal melodic role with the solo instrument, Bach in effect turned a solo instrumental work into a Trio Sonata. The three parts include the treble solo instrument, the keyboardist’s right hand, and the bass (played by keyboardist’s left hand, possibly doubled by a bass instrument). While Bach also wrote standard sonatas with continuo, he composed numerous obbligato sonatas for violin, flute, viola da gamba, and oboe. As in much of Bach’s music, the three parts engage in highly contrapuntal conversation, and often virtuosic elaboration.

The preceding examples suggest that instrumental chamber music dominated the scene at Sanssouci. But vocal music was also well-established at Frederick’s court. Indeed, the brilliant Carl Heinrich Graun (1704-1759) composed an opera for Frederick’s marriage in 1733 and became Kapellmeister in 1740. He was thus a colleague and contemporary of Quantz. And like Quantz, Graun came to musical maturity in the glittering, cosmopolitan court at Dresden before accepting a position under the new Prussian king. Graun was a notable tenor, a detail that helps explain the great emphasis he placed on opera. He did compose chamber music as well, but it is for operas – principally Cesare e Cleopatra (1742) and Montezuma (1755) – that Graun is still highly regarded, though rarely heard, today. For instance, the latter work was not heard in modern times until 1973 and less than a dozen times worldwide since then.

Montezuma relates pivotal events surrounding the Spanish conquest of the Americas. Looking back, we recognize this event as part of a larger human catastrophe that wiped out most of the indigenous peoples in the Western hemisphere. But for Enlightenment-era monarchs like Frederick, Cortes’ conquest of Montezuma and his empire provided the allure of international power politics, coupled with the exotic allure of distant lands and the noble figure of the ill-fated Aztec king. In fact, Frederick himself penned the original French libretto, subsequently translated into Italian to comply with prevailing tastes. There is an additional religious element, however. As a devout Protestant, Frederick’s loyalties devolve on the tragic yet naive figure of Montezuma, the victim of a bloodthirsty Catholic invader.

Our program closes with two of Montezuma’s arias from Act III. The title role was originally created for a castrato but is normally performed, as today, by male countertenor. The first, “Ah, d’inflessibil sorte,” features minimal accompaniment of plucked strings, thereby compelling all attention to fall directly on the powerful solo voice. Montezuma laments his condition as a victim of “rigid fate.” The second aria, “Si, corona,” shows the Aztec king in a more animated vein, lecturing Cortes on the consequences of his hubris. Graun’s writing calls forth acrobatic leaps and quicksilver scales from his lead role. By featuring Montezuma rather than Cortes, Quantz and Frederick reveal where their sympathies lay.

Jason Stell, © 2025