According to Johann Nikolaus Forkel’s 1802 biography of Bach, the Goldberg Variations were commissioned by the Russian ambassador to the Saxon court at Dresden, Count Carl von Keyserlingk, for his private harpsichordist, Johann Gottlieb Goldberg, to play to him during his sleepless nights. Forkel relates that the Count referred to them as “his” variations,  and rewarded the composer with a golden goblet filled with louis-d’or. As Christoph Wolff has pointed out, however, the variations most likely did not originate as an independently commissioned work, but were conceived from the outset as the finale to Bach’s monumental four-part Clavier-Übung (Keyboard Practice). More to the point, then, than Forkel’s charming anecdote would be the remark in the obituary by Carl Philipp Emanuel Bach and Johann Friedrich Agricola: “He needed only to have heard any theme to be aware — it seemed in the same instant — of almost every intricacy that artistry could produce in the treatment of it.”

French harpsichordist Jean Rondeau performed the complete Goldberg Variations (BWV 988) at the First Church, Congregational, in Cambridge on Friday for the Boston Early Music Festival series. Trained in jazz and improvisation and also conducting as well as in organ and piano, and still in his twenties, Rondeau  showed a deep awareness of both the larger structure of the entire cycle and the special qualities of individual variations. Keeping it all together, and holding our engaged attention for an hour and a half without intermission, was first of all his unfailing sense of rhythm. Notes were stretched or shrunk, suspenseful pauses intervened, the underlying pulse established for each movement always recovered its equilibrium. Tonal variety was another important element of Rondeau’s approach. Playing on a fine French-style double manual harpsichord by Allan Winkler, after the early 18th century Lyons maker Pierre Donzelague, he displayed a range of singing and staccato tones as well as breathtaking passage work.

The 30 variations are grouped in 10 sets of three, within the twin pillars of the Aria, stated at the beginning and again at the end. With the exception of Variation 27, which is unaccompanied, the third variation of each set is a two-voice canon with free accompaniment. The “Aria” is a Sarabande, a stately dance of Spanish origin in ternary meter with gentle stress on the second beat. Like most Baroque dances, it is divided into two sections, the first progressing to the dominant, the second returning to the tonic, and both sections are marked with repeat signs. The phrase structure of this particular sarabande is unusually  symmetrical, with units of 2 + 2 + 4 + 4 measures in each half. From the complex of melody, bass line, and middle voice, Bach chose the underlying harmonic progression, measure by measure, as the basis for his variations. After an introductory improvisation to “try out” the keyboard, Rondeau launched into the Sarabande-Aria at a leisurely pace, savoring the highly ornamented melody in the right hand. Bach wrote out many of the ornaments  meticulously, as if to discourage the player from adding his own; others, just as important, he indicated with the  conventional signs for slides, mordents, trills, etc. Rondeau rendered the ornaments in an introspective, searching style that resulted in our hearing them as an essential part of the melodic line. The basis of the variations now clearly established, he brought out the cohesiveness of the first three variations as a set. Variation 1 seemed to revert to a simpler texture, that of a two-part invention, with short motives, often in imitation, exchanged between the hands. In Variation 2, in three parts with a pseudo-canonic beginning, harmonies changed every two instead of every three beats. Further increase of rhythmic and textural density obscured the contrapuntal intricacies of Variation 3, a canon at the unison, as six 8ths replaced four, rapid 16th notes were heard in the bass as well as in the upper parts, and a brief new motive enlivened the canon. The interval of imitation progressed in each succeeding canon, from the unison of Variation 3 to the 9th of Variation 27. Variations 12 (at the 4^th) and 15 (at the 5^th) proceed by inversion: rising motion in the leading voice is answered by descending motion in the following voice and vice versa. Finally, Variation 30 is a Quodlibet that in lieu of a canon humorously combines two popular songs in free imitation with an ornamented version of the bass line. Rondeau appeared to follow what may have been Bach’s intent: each canon was interpreted according to its own inherent character, without any attempt to highlight its contrapuntal artifice by undue emphasis on canonic entries, which, often enough, were subtly camouflaged.

In addition to the opening sarabande, three more variations conveyed the distinct character of a dance. Opening the second set, and contrasting with the smoothly running 16^ths of the previous canon, Variation 4 was a sprightly passepied , full of leaps and syncopations. In his own copy of the Variations, Bach marked Variation 7 “al tempo di Giga” (in the tempo of a Gigue), probably to distinguish its pointedly dotted 8^ths from a more leisurely siciliano tempo. No tempo was indicated for Variation 19, but the character of a quick minuet is suggested by consistent emphasis on the second beat in 3/8 time. Another self-consciously designated character piece” is the  “Ouverture” that marks the beginning of the second half of the variation set. Following the schema of a French operatic overture, a stately opening section in slow duple time is followed by a fugal section in quick triple time.

By Bach’s time, a self-consciously archaic style of vocal counterpoint modelled on Palestrina was known as the stile antico. Two of the Goldberg Variations employ this manner, notated with a cut-C time signature with the beat falling on the half-note. Variation 18, a canon at the 6th, is similar in texture to the non-canonic Variation 22, labelled “alla breve,”  and the two movements are motivically similar as well. Three variations in the minor mode are also interrelated by their harmonic intensity and heightened emotional tone.  Variation 15, a canon at the 5^th by inversion, introduced chromatic pitches and syncopations and concluded the first half of the entire cycle by climbing to a high d”’. Variation 21, a canon at the 7^th, was considerably more chromatic and denser in texture that Variation 15. The highest point of emotional intensity was reached in Variation 25. Here an intensely chromatic and ornate solo voice, full of anguished leaps and wayward turns, floated over an expressive two-voice accompaniment.

Dispersed among the ingenious canons and expressive character pieces in ascending order of difficulty, variations for one or two keyboards involved much interweaving of lines and crossing of hands. Crossing melodic lines and  arpeggios, a single highly ornamented melody set off against a two-voice accompaniment, studies in textural contrast, single and double and even chordal trills, were all breathtaking in their exuberant virtuosity. Rondeau’s sure pacing made the most dazzling displays of virtuosity seem entirely natural and, indeed, inevitable explorations of what the two keyboards could produce in the hands of a thoughtful interpreter.

Virginia Newes, who lives in Cambridge, was Associate Professor of Music History and Musicology at the Eastman School of Music.