Overview
Introduction
The Great Eighteen Chorale Preludes, BWV 651–668, are a set of chorale preludes for organ prepared by Johann Sebastian Bach in Leipzig in his final decade (1740–1750), from earlier works composed in Weimar, where he was court organist. The works form an encyclopedic collection of large-scale chorale preludes, in a variety of styles harking back to the previous century, that Bach gradually perfected during his career. Together with the Orgelbüchlein, the Schübler Chorales and the third book of the Clavier-Übung, they represent the summit of Bach's sacred music for solo organ.
History
Early versions of almost all the chorale preludes are thought to date back to 1710–1714, during the period 1708–1717 when Bach served as court organist and Konzertmeister (director of music) in Weimar, at the court of Wilhelm Ernst, Duke of Saxe-Weimar. As a result of encouragement from the Duke, a devout Lutheran and music lover, Bach developed secular and liturgical organ works of all forms, in what was to be his most productive period for organ composition. As his son Carl Philipp Emanuel Bach mentions in his obituary or nekrolog: "His grace's delight in his playing fired him to attempt everything possible in the art of how to treat the organ. Here he also wrote most of his organ works." During Bach's time at Weimar, the chapel organ there was extensively improved and enlarged; occupying a loft at the east end of the chapel just below the roof, it had two manual keyboards, a pedalboard and about a dozen stops, including at Bach's request a row of tuned bells. It is probable that the longer chorale preludes composed then served some ceremonial function during the services in the court chapel, such as accompanying communion.
When Bach moved to his later positions as Kapellmeister in Köthen in 1717 and cantor at the Thomaskirche in Leipzig in 1723, his obligations did not specifically include compositions for the organ. The autograph manuscript of the Great Eighteen, currently preserved as P 271 in the Berlin State Library, documents that Bach began to prepare the collection around 1740, after having completed Part III of the Clavier-Übung in 1739. The manuscript is made up of three parts: the six trio sonatas for organ BWV 525–530 (1727–1732); the Canonic Variations on "Vom Himmel hoch da komm' ich her" BWV 769 added at the same time as the chorale preludes (1739–1750); and an early version of Nun komm' der heiden Heiland (1714–1717), appended after Bach's death.
The first thirteen chorale preludes BWV 651–663 were added by Bach himself between 1739 and 1742, supplemented by BWV 664 and 665 in 1746–7. In 1750 when Bach began to suffer from blindness before his death in July, BWV 666 and 667 were dictated to his student and son-in-law Johann Christoph Altnikol and copied posthumously into the manuscript. Only the first page of the last choral prelude BWV 668, the so-called "deathbed chorale", has survived, recorded by an unknown copyist. The piece was posthumously published in 1751 as an appendix to the Art of the Fugue, with the title "Wenn wir in höchsten Nöthen sein" (BWV 668a), instead of the original title "Vor deinen Thron tret ich hiermit" ("Before your throne I now appear").
There have been various accounts of the circumstances surrounding the composition of this chorale. The biographical account from 1802 of Johann Nicolaus Forkel that Altnikol was copying the work at the composer's deathbed has since been discounted: in the second half of the eighteenth century, it had become an apocryphal legend, encouraged by Bach's heirs, Carl Philipp Emmanuel Bach and Wilhelm Friedmann Bach. The piece, however, is now accepted as a planned reworking of the shorter chorale prelude Wenn wir in höchsten Nöthen sein (BWV 641) from the Orgelbüchlein (c 1715).
Compositional models
The breadth of styles and forms represented by the Great Eighteen is as diverse as that of Bach's Well Tempered Clavier for the keyboard. The pieces are on a large and often epic scale, compared with the miniature intimacy of the choral preludes of the Orgelbüchlein. Many of the chorale preludes pay homage to much older models in the German liturgical tradition (Georg Böhm, Buxtehude and Pachelbel), but the parallel influence of the Italian concerto tradition is equally visible. It is a mid-eighteenth century salute to the musical traditions of the previous century. Unlike Part III of the Clavier-Übung, where Bach pushed his compositional techniques for the organ to new limits, the chorale settings of Bach's Great Eighteen represent "the very quintessence of all he elaborated in Weimar in this field of art;" they "transcend by their magnitude and depth all previous types of choral prelude"; and they display a "workmanship as nearly flawless as we have any right to expect of a human being." The eighteen are characterized by their freely developed and independent accompaniment filling the long intervals between the successive lines of the cantus firmus, a feature of their large scale which has not pleased all commentators.
Chorale motet
The Renaissance motet, in madrigal style, forms the model for the chorale motet, used in BWV 665 and 666. Each line of the chorale is established as a point of imitation for the different parts, which keep to a common rhythm. This style, the earliest used by Bach, was that employed in his Mühlhausen cantatas, such as the funeral cantata Actus Tragicus, BWV 106. A common distinctive feature is the use of musical figures to illustrate particular lines or even words in the hymn text.
Chorale partita
The chorale partita is a set of variations on a chorale melody. Normally each variation repeats the chorale melody and is essentially a separate movement. This style goes back to the Dutch composer Sweelinck and was adopted by his German pupils Scheidt and Scheidemann; the tradition was continued at the turn of the 18th century by Georg Böhm and Pachelbel from Thuringia, who provided the model for Bach. Bach, however, broke the norm in the two chorale preludes of this genre, BWV 656 and 667, which each have only a small number of variations (3 and 2). This might be a homage to Buxtehude, who had written similar partitas and whose music and virtuosity at the organ is known to have exercised a considerable influence on Bach in his youth.
Ornamental chorale
In the ornamental chorale, a form invented and popularized in Northern Germany by Scheidemann, the chorale melody is taken by one voice in an elaborate and highly embellished form. Buxtehude was one of its most celebrated exponents, with his individual expressive "vocal" ornamentation.
Five chorale preludes of the Great Eighteen were written in this style: BWV 652, 653, 654, 659 and 662.
Cantus firmus chorale
The cantus firmus chorale: The melody of the chorale is sounded in long notes throughout the piece, was established and popularized in central Germany by Pachelbel. One of his students was Johann Christoph Bach III, Bach's older brother, who in turn taught Bach keyboard technique. There are six examples of the cantus firmus chorale: BWV 651, 657, 658, 661, 663 and 668.
Chorale trio
The chorale trio has the form of a trio sonata in which the upper parts are played on the two keyboards of the organ and the basso continuo part is played on the pedals. Bach elevated this form to the status of contemporary Italian trio sonatas or double concertos of Antonio Vivaldi and Giuseppe Torelli: it is probably his single most original innovation in the repertoire of organ chorales. The three virtuosic chorale preludes of this type are BWV 655, 660 and 664.
