Johann Sebastian Bach () (21 March 1685 O.S. – 28 July 1750 N.S.) was a prolific German composer and organist whose sacred and secular works for choir, orchestra, and solo instruments drew together the strands of the Baroque period and brought it to its ultimate maturity. Although he introduced no new forms, he enriched the prevailing German style with a robust contrapuntal technique, a control of harmonic and motivic organisation from the smallest to the largest scales, and the adaptation of rhythms and textures from abroad, particularly Italy and France.

Revered for their intellectual depth and technical and artistic beauty, Bach's works include the Brandenburg concertos; the Goldberg Variations; the English Suites, French Suites, Partitas, and Well-Tempered Clavier; the Mass in B Minor; the St Matthew Passion; the St. John Passion; The Musical Offering; The Art of Fugue; the Sonatas and Partitas for violin solo; the Cello Suites; more than 200 surviving cantatas; and a similar number of organ works, including the celebrated Toccata and Fugue in D Minor. Bach was not always appreciated during his own lifetime, and he was considered to be "old-fashioned" by his contemporaries, especially late in his career during the Rococo period. Nevertheless, Bach is now considered one of the most famous and influential composers of all time.

Johann Sebastian Bach was born in Eisenach, Thuringia. He was the youngest child of Johann Ambrosius Bach, an organist at St. George's Church, and Maria Elisabetha Lämmerhirt Bach. His father taught him to play violin and harpsichord. His uncles were all professional musicians, whose posts ranged from church organists and court chamber musicians to composers. One uncle, Johann Christoph Bach (1645–93), was especially famous and introduced him to the art of organ playing. Bach was proud of his family's musical achievements, and around 1735 he drafted a genealogy, "Origin of the musical Bach family", printed in translation in The Bach Reader (ISBN 0393002594).

Bach's mother died in 1694, and his father eight months later. The 10-year-old orphan moved in with his oldest brother, Johann Christoph Bach (1671–1721), the organist at nearby Ohrdruf. There, he copied, studied and performed music, and apparently received valuable teaching from his brother, who instructed him on the clavichord. JC Bach exposed him to the works of the great South German composers of the day, such as Johann Pachelbel (under whom Johann Christoph had studied) and Johann Jakob Froberger; possibly to the music of North German composers, to Frenchmen, such as Jean-Baptiste Lully, Louis Marchand, Marin Marais; and to the Italian clavierist Girolamo Frescobaldi. The young Bach probably witnessed and assisted in the maintenance of the organ music. Bach's obituary indicates that he copied music out of Johann Christoph's scores, but his brother had apparently forbidden him to do so, possibly because scores were valuable and private commodities at the time.

At the age of 14, Bach, along with his older school friend George Erdmann, was awarded a choral scholarship to study at the prestigious St. Michael’s School in Lüneburg, not far from the northern seaport of Hamburg, one of the largest cities in the Holy Roman Empire. This involved a long journey with his friend, probably undertaken partly on foot and partly by coach. His two years there appear to have been critical in exposing him to a wider palette of European culture than he would have experienced in Thuringia. In addition to singing in the a cappella choir, it is likely that he played the School’s three-manual organ and its harpsichords. He probably learned French and Italian, and received a thorough grounding in theology, Latin, history, geography, and physics. He would have come into contact with sons of noblemen from northern Germany sent to the highly selective school to prepare for careers in diplomacy, government, and the military. It is likely that he had significant contact with organists in Lüneburg, in particular Georg Böhm, and that he visited several of them in Hamburg, such as Johann Adam Reincken and Nicolaus Bruhns. Through these musicians, he probably gained access to the largest and finest instruments he had played thus far. It is likely that during this stage he became acquainted with the music of the German organ schools, especially the work of Dieterich Buxtehude, and with music manuscripts and treatises on music theory that were in the possession of these musicians.

In January 1703, shortly after graduating, Bach took up a post as a court musician in the chapel of Duke Johann Ernst in Weimar, a large town in Thuringia. His role there is unclear, but appears to have included menial, non-musical duties. During his seven-month tenure at Weimar, his reputation as a keyboard player spread. He was invited to inspect and give the inaugural recital on the new organ at St Boniface’s Church in Arnstadt. The Bach family had close connections with this oldest town in Thuringia, about 180 km to the southwest of Weimar at the edge of the great forest. In August 1703, he accepted the post of organist at that church, with light duties, a relatively generous salary, and a fine new organ tuned to a modern system that allowed a wide range of keys to be used. At this time, Bach was embarking on the serious composition of organ preludes; these works, in the North German tradition of virtuosic, improvisatory preludes, already showed tight motivic control (where a single, short music idea is explored cogently throughout a movement). However, in these works the composer had yet to fully develop his powers of large-scale organisation and his contrapuntal technique (where two or more melodies interact simultaneously).

Strong family connections and a musically enthusiastic employer failed to prevent tension between the young organist and the authorities after several years in the post. He was apparently dissatisfied with the standard of singers in the choir; more seriously, there was his unauthorised absence from Arnstadt for several months in 1705–06, when he visited the great master Dieterich Buxtehude and his Abendmusik in the northern city of Lübeck. This well-known incident in Bach’s life involved his walking some 400 kilometres () each way to spend time with the man he probably regarded as the father-figure of German organists. The trip reinforced Buxtehude’s style as a foundation for Bach’s earlier works, and that he overstayed his planned visit by several months suggests that his time with the old man was of great value to his art.

Despite his comfortable position in Arnstadt, by 1706 Bach appeared to have realised that he needed to escape from the family milieu and move on to further his career. He was offered a more lucrative post as organist at St Blasius’s in Mühlhausen, a large and important city to the north. The following year, he took up this senior post with significantly improved pay and conditions, including a good choir. Four months after arriving at Mühlhausen, he married his second cousin from Arnstadt, Maria Barbara Bach. They had seven children, four of whom survived to adulthood. Two of them—Wilhelm Friedemann Bach and Carl Philipp Emanuel Bach—became important composers in the ornate Rococo style that followed the Baroque.

The church and city government at Mühlhausen must have been proud of their new musical director. They readily agreed to his plan for an expensive renovation of the organ at St Blasius’s, and were so delighted at the elaborate, festive cantata he wrote for the inauguration of the new council in 1708—God is my king BWV 71, clearly in the style of Buxtehude—that they paid handsomely for its publication, and twice in later years had the composer return to conduct it. However, that same year, Bach was offered a better position in Weimar.

After barely a year at Mühlhausen, Bach left to become the court organist and concert master at the ducal court in Weimar, a far cry from his earlier position there as ‘lackey’. The munificent salary on offer at the court and the prospect of working entirely with a large, well-funded contingent of professional musicians may have prompted the move. The family moved into an apartment just five minutes’ walk from the ducal palace. In the following year, their first child was born and they were joined by Maria Barbara’s elder, unmarried sister, who remained with them to assist in the running of the household until her death in 1729. It was in Weimar that the two musically significant sons were born—Wilhelm Friedemann and Carl Philipp Emanuel Bach.

Bach’s position in Weimar marked the start of a sustained period of composing keyboard and orchestral works, in which he had attained the technical proficiency and confidence to extend the prevailing large-scale structures and to synthesise influences from abroad. From the music of Italians such as Vivaldi, Corelli and Torelli, he learnt how to write dramatic openings and adopted their sunny dispositions, dynamic motor-rhythms and decisive harmonic schemes. Bach inducted himself into these stylistic aspects largely by transcribing for harpsichord and organ the ensemble concertos of Vivaldi; these works are still concert favourites. He may have picked up the idea of transcribing the latest fashionable Italian music from Prince Johann Ernst, one of his employers, who was a musician of professional calibre. In 1713, the Duke returned from a tour of the Low Countries with a large collection of scores, some of them possibly transcriptions of the latest fashionable Italian music by the blind organist Jan Jacob de Graaf. Bach was particularly attracted to the Italian solo-tutti structure, in which one or more solo instruments alternate section-by-section with the full orchestra throughout a movement. These Italianate features can be heard in the excerpt below of the Prelude from English Suite No. 3 for harpsichord (1714). The solo–tutti alternation is achieved when the player deftly changes between the lower keyboard (of a fuller, slightly louder tone) and the upper keyboard (of a more delicate tone).

In Weimar, he had the opportunity to play and compose for the organ, and to perform a varied repertoire of concert music with the duke’s ensemble. A master of contrapuntal technique, Bach’s steady output of fugues began in Weimar. The largest single body of his fugal writing is Das wohltemperierte Clavier ("The well-tempered keyboard"—"Clavier" meaning keyboard instrument). It consists of 48 preludes and fugues, one pair for each major and relative minor key. This is a monumental work for its masterful use of counterpoint and its exploration, for the first time, of the full range of keys — and the means of expression made possible by their slight differences from each other—available to keyboardists when their instruments are tuned according to systems such as that of Andreas Werckmeister.

During his tenure at Weimar, Bach started work on The little organ book for his eldest son, Wilhelm Friedemann; this contains traditional Lutheran chorales (hymn tunes), set in complex textures to assist the training of organists. The book illustrates two major themes in Bach’s life: his dedication to teaching and his love of the chorale as a musical form.

Bach began once again to search out a more stable job that was conducive to his musical interests. Prince Leopold of Anhalt-Cöthen hired Bach to serve as his Kapellmeister (director of music). Prince Leopold, himself a musician, appreciated Bach’s talents, paid him well, and gave him considerable latitude in composing and performing. However, the prince was Calvinist and did not use elaborate music in his worship; thus, most of Bach’s work from this period was secular, including the Orchestral suites, the Six suites for solo cello and the Sonatas and partitas for solo violin. This photograph of the opening page of the first violin sonata shows the composer’s handwriting—fast and efficient, but just as visually ornate as the music it encoded. The well-known Brandenburg concertos date from this period.

On July 7 1720, while Bach was abroad with Prince Leopold, tragedy struck: his wife, Maria Barbara, the mother of his first 7 children, died suddenly. The following year, the widower met Anna Magdalena Wilcke, a young, highly gifted soprano 17 years his junior, who performed at the court in Cöthen; they married on 3 December 1721. Together they had 13 more children, six of whom survived into adulthood: Gottfried Heinrich, Johann Christoph Friedrich and Johann Christian all of whom became significant musicians; Elisabeth Juliane Friederica (1726–81) who married Bach's pupil Johann Christoph Altnikol, Johanna Carolina (1737–81) and Regina Susanna (1742–1809)

In 1723, Bach was appointed Cantor of Thomasschule, adjacent to the Thomaskirche (St Thomas’s Lutheran Church) in Leipzig, as well as Director of Music in the principal churches in the town. This was a prestigious post in the leading mercantile city in Saxony, a neighbouring electorate to Thuringia. Apart from his brief tenures in Arnstadt and Mühlhausen, this was Bach’s first government position in a career that had mainly involved service to the aristocracy. This final post, which he held for 27 years until his death, brought him into contact with the political machinations of his employer, the Leipzig Council. The Council comprised two factions: the Absolutists, loyal to the Saxon monarch in Dresden, Augustus the Strong; and the City-Estate faction, representing the interests of the mercantile class, the guilds and minor aristocrats. Bach was the nominee of the monarchists, in particular of the Mayor at the time, Gottlieb Lange, a lawyer who had earlier served in the Dresden court. In return for agreeing to Bach’s appointment, the City-Estate faction was granted control of the School, and Bach was required to make a number of compromises with respect to his working conditions. Although it appears that no one on the Council doubted Bach’s musical genius, there was continual tension between the Cantor, who regarded himself as the leader of church music in the city, and the City-Estate faction, which saw him as a schoolmaster and wanted to reduce the emphasis on elaborate music in both the School and the Churches. The Council never honoured Lange’s promise at interview of a handsome salary of 1,000 talers a year, although it did provide Bach and his family with a smaller income and a good apartment at one end of the school building, which was renovated at great expense in 1732.

Bach’s job required him to instruct the students of the Thomasschule in singing, and to provide weekly music at the two main churches in Leipzig, St Thomas's and St Nicholas's. His post also obliged him to teach Latin, but he was allowed to employ a deputy to do this instead. In an astonishing burst of creativity, he wrote up to five annual cantata cycles during his first six years in Leipzig (two of which have apparently been lost). Most of these concerted works expound on the Gospel readings for every Sunday and feast day in the Lutheran year; many were written using traditional church hymns, such as Wachet auf! Ruft uns die Stimme and Nun komm, der Heiden Heiland, as inspiration.



To rehearse and perform these works at St Thomas’s Church, Bach probably sat at the harpsichord or stood in front of the choir on the lower gallery at the west end, his back to the congregation and the altar at the east end. He would have looked upwards to the organ that rose from a loft about four metres above. To the right of the organ in a side gallery would have been the winds, brass and timpani; to the left were the strings. The Council provided only about eight permanent instrumentalists, a source of continual friction with the Cantor, who had to recruit the rest of the 20 or so players required for medium-to-large scores from the University, the School and the public. The organ or harpsichord were probably played by the composer (when not standing to conduct), the in-house organist, or one of Bach’s elder sons, Wilhelm Friedemann or Carl Philipp Emanuel.

Bach drew the soprano and alto choristers from the School, and the tenors and basses from the School and elsewhere in Leipzig. Performing at weddings and funerals provided extra income for these groups; it was probably for this purpose, and for in-school training, that he wrote at least six motets, mostly for double-choir. As part of his regular church work, he performed motets of the Venetian school and Germans such as Heinrich Schütz, which would have served as formal models for his own motets. The audio excerpt is from the opening of Singet dem Herrn (Sing to the Lord), showing the rich, energetic textures that Bach could produce with two choirs, each in four parts.



Having spent much of the 1720s composing cantatas, Bach had assembled a huge repertoire of church music for Leipzig’s two main churches. He now wished to broaden his composing and performing beyond the liturgy. In March 1729, he took over the directorship of the Collegium Musicum, a secular performance ensemble that had been started in 1701 by his old friend, the composer Georg Philipp Telemann. This was one of the dozens of private societies in the major German-speaking cities that had been established by musically active university students; these societies had come to play an increasingly important role in public musical life and were typically led by the most prominent professionals in a city. In the words of Christoph Wolff, assuming the directorship was a shrewd move that 'consolidated Bach’s firm grip on Leipzig’s principal musical institutions’. During much of the year, Leipzig’s Collegium Musicum gave twice-weekly, two-hour performances in Zimmerman’s Coffeehouse on Catherine Street, just off the main market square. For this purpose, the proprietor provided a large hall and acquired several musical instruments. Many of Bach’s works during the 1730s, 40s and 50s were probably written for and performed by the Collegium Musicum; among these were almost certainly parts of the Clavier-Übung (Keyboard Practice), and many of the violin and harpsichord concertos.



During this period, he composed the Kyrie and Gloria of the Mass in B Minor, and in 1733, he presented the manuscript to the Elector of Saxony in an ultimately successful bid to persuade the monarch to appoint him as Royal Court Composer. He later extended this work into a full Catholic Mass, by adding a Credo, Sanctus and Agnus Dei, the music for which was almost wholly taken from some of the best of his cantata movements. Bach's appointment as court composer appears to have been part of his long-term struggle to achieve greater bargaining power with the Leipzig Council. The audio excerpt, from one of the movements that was presented to the monarch, shows his use of festive trumpets and timpani. Although the complete mass was probably never performed during the composer’s lifetime, it is considered to be among the greatest choral works of all time. Between 1737 and 1739, Bach's former pupil Carl Gotthelf Gerlach took over the directorship of the Collegium Musicum.

In 1747, Bach went to the court of Frederick II of Prussia in Potsdam, where the king played a theme for Bach and challenged him to improvise a fugue based on his theme. Bach improvised a three-part fugue on Frederick’s pianoforte, then a novelty, and later presented the king with a Musical Offering which consists of fugues, canons and a trio based on the "royal theme", nominated by the monarch. Its six-part fugue includes a slightly altered subject more suitable for extensive elaboration.

The Art of Fugue, published posthumously but probably written years before Bach's death, is unfinished. It consists of 18 complex fugues and canons based on a simple theme. A magnum opus of thematic transformation and contrapuntal devices, this work is often cited as the summation of polyphonic techniques.

The final work Bach completed was a chorale prelude for organ, dictated to his son-in-law, Johann Altnikol, from his deathbed. Entitled Vor deinen Thron tret ich hiermit (Before thy throne I now appear); when the notes on the three staves of the final cadence are counted and mapped onto the Roman alphabet, the initials "JSB" are found. The chorale is often played after the unfinished 14th fugue to conclude performances of The Art of Fugue.

Bach became increasingly blind, and the celebrated British ophthalmologist John Taylor (who had operated unsuccessfully on Handel) operated on Bach while visiting Leipzig in 1750. However Bach died "from the unhappy consequences of the very unsuccessful eye operation" at the age of 65. His estate was valued at 1159 Thalers and included 5 Clavecins, 2 Lute-Harpsichords, 3 violins, 3 violas, 2 cellos, a viola da gamba, a lute and a spinet, 52 "Sacred Books" (many by Martin Luther, Muller and Pfeiffer, also including Josephus's History of the Jews and 9 volumes of Wagner's Leipzig Song Book).

During his life he composed more than 1,000 works.

At Leipzig, Bach seems to have maintained active relationships with several members of the faculty of the university. He enjoyed a particularly fruitful relationship with the poet Picander. Sebastian and Anna Magdalena welcomed friends, family, and fellow musicians from all over Germany into their home. Court musicians at Dresden and Berlin, and musicians including Georg Philipp Telemann (one of Emanuel’s godfathers) made frequent visits to Bach’s apartment and may have kept up frequent correspondence with him. Interestingly, George Frideric Handel, who was born in the same year as Bach in Halle, only 50 km from Leipzig, made several trips to Germany, but Bach was unable to meet him, a fact that Bach appears to have deeply regretted.

Bach’s musical style arose from his extraordinary fluency in contrapuntal invention and motivic control, his flair for improvisation at the keyboard, his exposure to South German, North German, Italian and French music, and his apparent devotion to the Lutheran liturgy. His access to musicians, scores and instruments as a child and a young man, combined with his emerging talent for writing tightly woven music of powerful sonority, appear to have set him on course to develop an eclectic, energetic musical style in which foreign influences were injected into an intensified version of the pre-existing German musical language. Throughout his teens and 20s, his output showed increasing skill in the large-scale organisation of musical ideas, and the enhancement of the Buxtehudian model of improvisatory preludes and counterpoint of limited complexity. The period 1713–14, when a large repertoire of Italian music became available to the Weimar court orchestra, was a turning point. From this time onwards, he appears to have absorbed into his style the Italians’ dramatic openings, clear melodic contours, the sharp outlines of their bass lines, greater motoric and rhythmic conciseness, more unified motivic treatment, and more clearly articulated schemes for modulation.

There are several more specific features of Bach's style. The notation of baroque melodic lines tended to assume that composers would write out only the basic framework, and that performers would embellish this framework by inserting ornamental notes and otherwise elaborating on it. Although this practice varied considerably between the schools of European music, Bach was regarded at the time as being on one extreme end of the spectrum, notating most or all of the details of his melodic lines—particularly in his fast movements—thus leaving little for performers to interpolate. This may have assisted his control over the dense contrapuntal textures that he favoured, which allow less leeway for the spontaneous variation of musical lines. Bach's contrapuntal textures tend to be more cumulative than those of Händel and most other composers of the day, who would typically allow a line to drop out after it had been joined by two or three others. Bach's harmony is marked by a tendency to employ brief tonicisation—subtle references to another key that lasts for only a few beats at the longest—particularly of the supertonic, to add colour to his textures.

At the same time, Bach, unlike later composers, left the instrumentation of major works including The Art of Fugue and The Musical Offering open. It is likely that his detailed notation was less an absolute demand on the performer and more a response to a 17th-century culture in which the boundary between what the performer could embellish and what the composer demanded to be authentic was being negotiated.

Bach’s apparently devout, personal relationship with the Christian God in the Lutheran tradition and the high demand for religious music of his times inevitably placed sacred music at the centre of his repertory; more specifically, the Lutheran chorale hymn tune, the principal musical aspect of the Lutheran service, was the basis of much of his output. He invested the chorale prelude, already a standard set of Lutheran forms, with a more cogent, tightly integrated architecture, in which the intervallic patterns and melodic contours of the tune were typically treated in a dense, contrapuntal lattice against relatively slow-moving, overarching statements of the tune.

Bach's theology also informed his compositional structures: Sei Gegrüsset is perhaps the finest example where there is a theme with 11 variations (making 12 movements) that, while still one work, becomes two sets of six—to match Lutheran preaching principles of repetition. At the same time the theological interpretation of 'master' and 11 disciples would not be lost on his contemporary audience. Further, the practical relationship of each variation to the next (in preparing registration and the expected textural changes) seems to show an incredible capacity to preach through the music using the musical forms available at the time.

Bach's deep knowledge of and interest in the liturgy led to his developing intricate relationships between music and linguistic text. This was evident from the smallest to the largest levels of his compositional technique. On the smallest level, many of his sacred works contain short motifs that, by recurrent association, can be regarded as pictorial symbolism and articulations of liturgical concepts. For example, the octave leap, usually in a bass line, represents the relationship between heaven and earth; the slow, repeated notes of the bass line in the opening movement of Cantata 106 (Gottes Zeit ist die allerbeste Zeit) depict the laboured trudging of Jesus as he was forced to drag the cross from the city to the crucifixion site.

On the largest level, the large-scale structure of some of his sacred vocal works is evidence of subtle, elaborate planning: for example, the overall form of the St Matthew Passion illustrates the liturgical and dramatic flow of the Easter story on a number of levels simultaneously; the text, keys and variations of instrumental and vocal forces used in the movements of Cantata 11 (Lobet Gott in seinen Reichen) may form a structure that resembles the cross.

Beyond these specific musical features arising from Bach’s religious affiliation is the fact that he was able to produce music for an audience that was committed to serious, regular worship, for which a concentrated density and complexity was accepted. His natural inclination may have been to reinvigorate existing forms, rather than to discard them and pursue more dramatic musical innovations. Thus, Bach’s inventive genius was almost entirely directed towards working within the structures he inherited, according to most critics and historians.

Bach’s inner personal drive to display his musical achievements was evident in a number of ways. The most obvious was his successful striving to become the leading virtuoso and improviser of the day on the organ. Keyboard music occupied a central position in his output throughout his life, and he pioneered the elevation of the keyboard from continuo to solo instrument in his numerous harpsichord concertos and chamber movements with keyboard obbligato, in which he himself probably played the solo part. Many of his keyboard preludes are vehicles for a free improvisatory virtuosity in the German tradition, although their internal organisation became increasingly more cogent as he matured. Virtuosity is a key element in other forms, such as the fugal movement from Brandenburg Concerto No. 4, in which Bach himself may have been the first to play the rapid solo violin passages. Another example is in the organ fugue from BWV547, a late work from Leipzig, in which virtuosic passages are mapped onto Italian solo-tutti alternation within the fugal development.

Related to his cherished role as teacher was his drive to encompass whole genres by producing collections of movements that thoroughly explore the range of artistic and technical possibilities inherent in those genres. The most famous examples are the two books of the Well Tempered Clavier, each of which presents a prelude and fugue in every major and minor key, in which a variety of contrapuntal and fugal techniques are displayed. The English and French Suites, and the Partitas, all keyboard works from the Cöthen period, systematically explore a range of metres and of sharp and flat keys. This urge to manifest structures is evident throughout his life: the Goldberg Variations (1746?), include a sequence of canons at increasing intervals (unison, seconds, thirds, etc.), and The Art of Fugue (1749) can be seen as a compendium of fugal techniques.

Bach married his second cousin Maria Barbara Bach in 1707. They had seven children, four of whom survived to adulthood: * Catharina Dorothea (* 28 December 1708; † 14 January 1774). * Wilhelm Friedemann (* 22 November 1710; † 1 July 1784). * Carl Philipp Emanuel (* 8 March 1714; † 14 December 1788). * Johann Gottfried Bernhard (* 11 May 1715; † 27 May 1739). Maria died in 1720, and Bach married Anna Magdalena Wilcke in 1721. They had a further thirteen children, six of whom survived to adulthood: * Gottfried Heinrich (* 1724; † 1763) * Elisabeth Juliana Friederica, called "Liesgen" (* 1726; † 1781) * Johann Christoph Friedrich, the 'Bückeburg' Bach (* 1732; † 1795) * Johann Christian, the 'London' Bach (* 1735; † 1782) * Johanna Carolina (* 1737; † 1781) * Regina Susanna (* 1742; † 1809)

J. S. Bach’s works are indexed with BWV numbers, an initialism for Bach Werke Verzeichnis (Bach Works Catalogue). The catalogue, published in 1950, was compiled by Wolfgang Schmieder. The catalogue is organised thematically, rather than chronologically: BWV 1–224 are cantatas, BWV 225–249 the large-scale choral works, BWV 250–524 chorales and sacred songs, BWV 525–748 organ works, BWV 772–994 other keyboard works, BWV 995–1000 lute music, BWV 1001–40 chamber music, BWV 1041–71 orchestral music, and BWV 1072–1126 canons and fugues. In compiling the catalogue, Schmieder largely followed the Bach Gesellschaft Ausgabe, a comprehensive edition of the composer's works that was produced between 1850 and 1905. For a list of works catalogued by BWV number, see List of compositions by Johann Sebastian Bach.

Bach was best known during his lifetime as an organist, organ consultant, and composer of organ works in both the traditional German free genres such as preludes, fantasias, and toccatas, and stricter forms such as chorale preludes and fugues. He established a reputation at a young age for his great creativity and ability to integrate foreign styles into his organ works. A decidedly North German influence was exerted by Georg Böhm, with whom Bach came into contact in Lüneburg, and Dieterich Buxtehude in Lübeck, whom the young organist visited in 1704 on an extended leave of absence from his job in Arnstadt. Around this time, Bach copied the works of numerous French and Italian composers to gain insights into their compositional languages, and later arranged violin concertos by Vivaldi and others for organ and harpsichord. His most productive period (1708–14) saw the composition of several pairs of preludes and fugues and toccatas and fugues, and of the Orgelbüchlein ("Little organ book"), an unfinished collection of 45 short chorale preludes that demonstrate compositional techniques in the setting of chorale tunes. After he left Weimar, Bach's output for organ fell off, although his best-known works (the six trio sonatas, the Clavierübung III of 1739, and the "Great eighteen" chorales, revised late in his life) were all composed after this time. Bach was extensively engaged later in his life in consulting on organ projects, testing newly built organs, and dedicating organs in afternoon recitals. One of the high points may be the third part of the Clavierübung, a setting of 21 chorale preludes uniting the traditional Catholic Missa with the Lutheran catechism liturgy, the whole set interpolated between a mighty Prelude and Fugue on the theme of the Trinity.

Bach wrote many works for the harpsichord, some of which may also have been played on the clavichord. Many of his keyboard works are anthologies that show an eagerness to encompass whole theoretical systems in an encyclopaedic fashion, as it were. * The Well-Tempered Clavier, Books 1 and 2 (BWV 846–893). Each book comprises a prelude and fugue in each of the 24 major and minor keys (thus, the whole collection is often referred to as ‘the 48’). “Well-tempered” in the title refers to the temperament (system of tuning); many temperaments before Bach’s time were not flexible enough to allow compositions to move through more than just a few keys. * The 15 Inventions and 15 Sinfonias (BWV 772–801). These are short two- and three-part contrapuntal works arranged in order of key signatures of increasing sharps and flats, omitting some of the less used ones. The pieces were intended by Bach for instructional purposes. * Three collections of dance suites: the English Suites (BWV 806–811), the French Suites (BWV 812–817) and the Partitas for keyboard (BWV 825–830). Each collection contains six suites built on the standard model (Allemande–Courante–Sarabande–(optional movement)–Gigue). The English Suites closely follow the traditional model, adding a prelude before the allemande and including a single movement between the sarabande and the gigue. The French Suites omit preludes, but have multiple movements between the sarabande and the gigue. The partitas expand the model further with elaborate introductory movements and miscellaneous movements between the basic elements of the model. * The Goldberg Variations (BWV 988), an aria with thirty variations. The collection has a complex and unconventional structure: the variations build on the bass line of the aria, rather than its melody, and musical canons are interpolated according to a grand plan. There are nine canons within the 30 variations, one placed every three variations between variations 3 and 27. These variations move in order from canon at the unison to canon at the ninth. The first eight are in pairs (unison and octave, second and seventh, third and sixth, fourth and fifth). The ninth canon stands on its own due to compositional dissimilarities. * Miscellaneous pieces such as the Overture in the French Style (French Overture, BWV 831) Chromatic Fantasia and Fugue (BWV 903), and the Italian Concerto (BWV 971).

Among Bach’s lesser known keyboard works are seven toccatas (BWV 910–916), four duets (BWV 802–805), sonatas for keyboard (BWV 963–967), the Six Little Preludes (BWV 933–938) and the Aria variata alla maniera italiana (BWV 989).

Bach wrote music for single instruments, duets and small ensembles. Bach's works for solo instruments – the six sonatas and partitas for violin (BWV 1001–1006), the six cello suites (BWV 1007–1012) and the Partita for solo flute (BWV 1013) – may be listed among the most profound works in the repertoire. Bach also composed a suite and several other works for solo lute. He wrote trio sonatas; solo sonatas (accompanied by continuo) for the flute and for the viola da gamba; and a large number of canons and ricercare, mostly for unspecified instrumentation. The most significant examples of the latter are contained in The Art of Fugue and The Musical Offering.

Bach's best-known orchestral works are the Brandenburg concertos, so named because he submitted them in the hope of gaining employment from Margrave Christian Ludwig of Brandenburg-Schwedt in 1721; his application was unsuccessful. These works are examples of the concerto grosso genre. Other surviving works in the concerto form include two violin concertos (BWV 1041, and BWV 1042); a Concerto for Two Violins in D Minor (BWV 1043), often referred to as Bach’s "double" concerto; and concertos for one, two, three and even four harpsichords. It is widely accepted that many of the harpsichord concertos were not original works, but arrangements of his concertos for other instruments now lost. A number of violin, oboe and flute concertos have been reconstructed from these. In addition to concertos, Bach also wrote four orchestral suites, a series of stylised dances for orchestra. The work now known as the Air on the G String is an arrangement for the violin made in the nineteenth century from the second movement of the Orchestral Suite No. 3.

Bach performed a cantata on Sunday at the Thomaskirche, on a theme corresponding to the lectionary readings of the week, as determined by the Lutheran Church Year calendar. He did not perform cantatas during the seasons of Lent and Advent. Although he performed cantatas by other composers, he also composed at least three entire sets of cantatas, one for each Sunday and holiday of the church year, at Leipzig, in addition to those composed at Mühlhausen and Weimar. In total he wrote more than 300 sacred cantatas, of which only about 195 survive.

His cantatas vary greatly in form and instrumentation. Some of them are only for a solo singer; some are single choruses; some are for grand orchestras, some only a few instruments. A very common format, however, includes a large opening chorus followed by one or more recitative-aria pairs for soloists (or duets), and a concluding chorale. The recitative is part of the corresponding Bible reading for the week and the aria is a contemporary reflection on it. The melody of the concluding chorale often appears as a cantus firmus in the opening movement. The best known of these cantatas are BWV 4 ("Christ lag in Todesbanden"), BWV 80 ("Ein' feste Burg"), BWV 140 ("Wachet auf") and BWV 147 ("Herz und Mund und Tat und Leben").

In addition, Bach wrote a number of secular cantatas, usually for civic events such as council inaugurations. These also include wedding cantatas, the Wedding Quodlibet, the Peasant Cantata and the Coffee Cantata, which concerns a girl whose father will not let her marry until she gives up her addiction to that extremely popular drink.

Bach’s large choral-orchestral works include the famous St Matthew Passion and St John Passion, both written for Good Friday vespers services at St Thomas’s and St Nicholas' Churches in alternate years, the Christmas Oratorio (a set of six cantatas for use in the Liturgical season of Christmas). The Magnificat in two versions (one in E-flat major, with four interpolated Christmas-related movements, and the later and better-known version in D major) and the Easter Oratorio compare to large, elaborated cantatas, of a lesser extent than the Passions and the Christmas Oratorio.

Bach's other large work, the Mass in B minor, was assembled by Bach near the end of his life, mostly from pieces composed earlier (such as cantata BWV 191 and BWV 12). It was never performed in Bach’s lifetime, or even after his death until the 19th century.

All of these works, unlike the six motets (Singet dem Herrn ein neues Lied; Der Geist hilft unser Schwachheit auf; Jesu, meine Freude; Fürchte dich nicht; Komm, Jesu, komm!; and Lobet den Herrn alle Heiden), have substantial solo parts as well as choruses.

Bach's copy of a two volume Bible commentary by the orthodox Lutheran theologian, Abraham Calov, was discovered in the 1950s in a barn in Minnesota, purchased apparently in Germany as part of a "job lot" of old books and brought to America by an immigrant. Its provenance was verified and it was subsequently deposited in the rare book holdings of Concordia Seminary in St. Louis, Missouri. It contains his markings of texts for his cantatas and notes. It is only rarely displayed to the public. A study of the so-called Bach Bible was prepared by Robin Leaver, titled J. S. Bach and Scripture: Glosses from the Calov Bible Commentary (St. Louis: Concordia Publishing House, 1985).

Present-day Bach performers may pursue either of two traditions: authentic performance practice, utilising historical techniques, or alternatively the use of modern instruments and playing techniques, with a tendency towards larger ensembles. In Bach’s time orchestras and choirs were usually smaller than those known to, for example, Brahms, and even Bach's most ambitious choral works, such as his Mass in B minor and Passions, are composed for relatively modest forces. Some of Bach's important chamber music does not indicate instrumentation, which gives greater latitude for variety of ensemble.

"Easy listening" realisations of Bach's music and its use in advertising also contributed greatly to Bach's popularisation in the second half of the twentieth century. Among these were the Swingle Singers' versions of Bach pieces that are now well-known (for instance, the Air on the G string, or the Wachet Auf chorale prelude) and Wendy Carlos' 1968 recording Switched-On Bach using the then recently-invented Moog synthesiser. Jazz musicians have also adopted Bach's music, with Jacques Loussier, Ian Anderson and Uri Caine among those creating jazz versions of Bach works.

In his later years and after his death, Bach's reputation as a composer declined; his work was regarded as old-fashioned compared to the emerging classical style. Initially he was remembered more as a player, teacher and as the father of his children, most notably Johann Christian and Carl Philipp Emanuel. (Two other children, Wilhelm Friedmann and Johann Christoph Friedrich, were also composers.)

During this time, his works for keyboard were those most appreciated and composers ever since have acknowledged his mastery of the genre. Mozart, Beethoven, and Chopin were among his most prominent admirers. On a visit to Thomasschule, for example, Mozart heard a performance of one of the motets (BWV 225) and exclaimed "Now, here is something one can learn from!"; on being given the motets' parts, "Mozart sat down, the parts all around him, held in both hands, on his knees, on the nearest chairs. Forgetting everything else, he did not stand up again until he had looked through all the music of Sebastian Bach". Beethoven was a devotee, learning the Well-Tempered Clavier as a child and later calling Bach the "Urvater der Harmonie" ("Original father of Harmony") and, in a pun on the literal meaning of Bach's name, "nicht Bach, sondern Meer" ("not a brook, but a sea"). Before performing a concert, Chopin used to lock himself away and play Bach's music. Several notable composers such as Mozart, Beethoven, Schumann and Mendelssohn began writing in a more contrapuntal style after being introduced to Bach's music. Today the "Bach style" continues to influence musical composition, from hymns and religious works to pop and rock. Many of Bach’s themes—particularly the theme from Toccata and Fugue in D minor—have been used in rock songs repeatedly and have received notable popularity.

The revival in the composer’s reputation among the wider public was prompted in part by Johann Nikolaus Forkel’s 1802 biography, which was read by Beethoven. Goethe became acquainted with Bach's works relatively late in life, through a series of performances of keyboard and choral works at Bad Berka in 1814 and 1815; in a letter of 1827 he compared the experience of listening to Bach's music to "eternal harmony in dialogue with itself". But it was Felix Mendelssohn who did the most to revive Bach's reputation with his 1829 Berlin performance of the St Matthew Passion. Hegel, who attended the performance, later called Bach a "grand, truly Protestant, robust and, so to speak, erudite genius which we have only recently learned again to appreciate at its full value". Mendelssohn's promotion of Bach, and the growth of the composer’s stature, continued in subsequent years. The Bach Gesellschaft (Bach Society) was founded in 1850 to promote the works, publishing a comprehensive edition over the subsequent half century.

Thereafter Bach’s reputation has remained consistently high. During the twentieth century, the process of recognising the musical as well as the pedagogic value of some of the works has continued, perhaps most notably in the promotion of the Cello Suites by Pablo Casals. Another development has been the growth of the "authentic" or period performance movement, which as far as possible attempts to present the music as the composer intended it. Examples include the playing of keyboard works on the harpsichord rather than a modern grand piano and the use of small choirs or single voices instead of the larger forces favoured by nineteenth- and early twentieth-century performers.

Johann Sebastian Bach’s contributions to music, or, to borrow a term popularised by his student Lorenz Christoph Mizler, his "musical science", are frequently bracketed with those by William Shakespeare in English literature and Isaac Newton in physics. Scientist and author Lewis Thomas once suggested how the people of Earth should communicate with the universe: "I would vote for Bach, all of Bach, streamed out into space, over and over again. We would be bragging of course, but it is surely excusable to put the best possible face on at the beginning of such an acquaintance. We can tell the harder truths later."

Some composers have paid tribute to Bach by setting his name in musical notes (B-flat, A, C, B-natural; B-natural is notated as "H" in German musical texts, whilst B-flat is just "B") or using contrapuntal derivatives. Liszt, for example, wrote a praeludium and fugue on this BACH motif (existing in versions both for organ and piano). Bach himself set the precedent for this musical acronym, most notably in Contrapunctus XIV from the Art of Fugue. Whereas Bach also conceived this cruciform melody (among other similar ones) as a sign of devotion to Christ and his cross, later composers have employed the BACH motif in homage to the composer himself.

Some of the greatest composers since Bach have written works which explicitly pay homage to him. Examples include Beethoven's Diabelli Variations, Shostakovich's Preludes and Fugues, Brahms's Cello Sonata in E, whose finale is based on themes from the Art of Fugue. A 20th century work very strongly influenced by Bach is Villa-Lobos's Bachianas brasileiras. Stephen Sondheim once claimed he listened to no one else except Bach.

He is commemorated as a musician in the Calendar of Saints of the Lutheran Church on July 28.

Bach is the most represented artist on the Voyager Golden Record, a phonograph record included in two Voyager missions. Bach's compositions comprise 3 of the 27 recordings chosen.

Although Bach had twenty children, only seven survived infancy. He has no known descendants living today. His great-granddaughter, Frau Carolina Augusta Wilhelmine Ritter, who died 13 May 1871, was his last known descendant.

* Butt, John (ed). The Cambridge companion to Bach (Cambridge, UK : Cambridge University Press, 1997) ISBN 0-521-45350-X (hbk.) ISBN 0-521-58780-8 (pbk.) ; (New York : Cambridge University Press, 1997) ISBN 0-521-45350-X (hbk.) ISBN 0-521-45962-1 (pbk.). *: A collection of writings on the historical context (society, beliefs and world view), profiles of his music, and influence and reception. * David, Hans Theodore, and Arthur Mendel (eds), revised and expanded by Christoph Wolff. The new Bach reader (New York : Norton, 1999) 2d ed. ISBN 0-393-31956-3. *: A significant repository of documentary evidence, including contemporary documents, some by Bach himself. This book includes an English translation of the biography of Bach by the early 19th-century German musicologist Forkel. * Wolff, Christoph. Johann Sebastian Bach: the learned musician (New York : Norton, 2000) ISBN 0-393-04825-X (hbk.) ; (New York : Norton, 2001) ISBN 0-393-32256-4 (pbk.). *: A comprehensive and engaging account of Bach's life. * Williams, Peter. The life of Bach (Cambridge, UK : Cambridge University Press, 2004) ISBN 0-521-82636-5 (hbk.) ISBN 0-521-53374-0 (pbk.). *: A shorter expose of the composer's life, using his obituary as the starting point; a valuable complement to Wolff's biography. * Stauffer, George, and Ernest May. J. S. Bach as organist: his instruments, music, and performance practices (Bloomington : Indiana University Press, 1986) ISBN 0-253-33181-1 (hbk.), (Bloomington : Indiana University Press, 1999) ISBN 0-253-21386-X (pbk.). * Boyd, Malcolm. Bach (Oxford : Oxford University Press, 2000) 3rd ed. ISBN 0-19-514222-5 (alk. paper), ISBN 0-19-514223-3 (pbk.). * Deutsch, Wilhelm Otto. "Gesten der Annahme, der Verwandlung, der Verwandtschft: Ein Beitrag zur musikalischen Hermeneutik J. S. Bachs in der h-moll-Messe", in Musik und Kirche volume lxii, number 6 (1992), pages 321-327, ISSN 0027-4771 (in German). * Wolff, Christoph et al. The New Grove Bach Family. Macmillan 1983 ISBN 0 333 34350 6 * *

* Schweitzer, Albert. J. S. Bach (New York : Dover, 1966) 2 volumes, translated by Ernest Newman, ISBN 0-486-21631-4, reprint of (New York : Macmillan, 1950, 1955, 1962, 1966). * Spitta, Philipp. Johann Sebastian Bach, his work and influence on the music of Germany, 1685-1750 (London : Novello, 1884) translated by Clara Bell and JA Fuller Maitland; see also (New York : Dover, 1951). : An early, groundbreaking, three-volume study of Bach's life and music. * Forkel, Johann Nicolaus. Johann Sebastian Bach; his life, art, and work (New York : Da Capo Press, 1970) Notes and appendices by Charles Sanford Terry, ISBN 0-306-70010-7, contains a translation of "Ueber Johann Sebastian Bachs Leben, Kunst und Kunstwerke : Für patriotische Verehrer echter musikalischer Kunst : Mit Bachs Bildnis und Kupfertafeln" (Leipzig : Hoffmeister und Kühnel, 1802). There is a 1999 reprint of the 1802 German edition by Bärenreiter Verlag, Kassel, Germany, ISBN 3-7618-1472-0. : An original biography of J. S. Bach written by a near-contemporary who was able to correspond with two of Bach's sons.

* Baron, C.K., (Editor), (2006) “Bach's Changing World” (The Boydell Press) Hofstadter, Douglas, Gödel, Escher, Bach: an eternal golden braid :Explores cognition, formal methods, logic and mathematics—particularly Gödel's incompleteness theorem—in the music of Bach, the art of MC Escher and other sources.

* Bach Network UK - enables contact between scholars and performers worldwide * Bach-Leipzig.de, Bach-Archiv Leipzig * The J. S. Bach Home Page - JSBach.org, by Jan Hanford - extensive information on Bach and his works; huge and growing database of user-contributed recordings and reviews * Dave's J. S. Bach Page - JSBach.net, maintained by Dave Grossman - includes a catalog of works, images, MIDI files, audio, and electric bass arrangements * Radio 3 - A Bach Christmas - extensive resources on Bach, on occasion of BBC Radio 3's complete airing of Bach's works in December 2005 * J. S. Bach bibliography, by Yo Tomita of Queen's Belfast - especially useful to scholars * Bach-Cantatas.com, by Aryeh Oron - information on the cantatas as well as other works * Canons and Fugues, by Timothy A. Smith - various information on these contrapuntal works * http://www.mckeeth.org/wikilinks/bach1911.html, http://www.kunstderfuge.com/bios/bach.html Grove Encyclopedia and Encyclopedia Britannica entry on J. S. Bach * Riemenschneider Bach Institute - includes partial catalog of works by Bach and his circle, information about the Bach Festival * Bacholoji, by Sami Yenice - include a searchable database of Bach's works, online radio and video. * Fugues of the Well-Tempered Clavier: Interactive scores calibrated to recordings by David Korevaar and analysis by Tim Smith. * Content about J. S. Bach - Dontbflat.com: Information about classical composers, book references and a colorful timeline * Julian Lloyd Webber plays Bach's famous Air on a G string (Aria from Suite in D)

* Piano Sheet Music of Compositions by Johann Sebastian Bach - Out of Copyright Editions * Free Scores by Johann Sebastian Bach at the International Music Score Library Project. * * * * Web Site in Korean dedicated to J. S. Bach - Almost every work available * Bach Gesellschaft Download Page - the BGA volumes available for download in DJVU format.

* Free MP3 recordings of the Motets http://humanneuro.physiol.umu.se/GW/3mp3/Der%20Geist%20hilft%204.mp3'>Der Geist hilft unsrer Schwachheit auf - BVW 226, http://humanneuro.physiol.umu.se/GW/2mp3/Jesu_Meine_Freude_BWB_227_2.mp3'>Jesu Meine Freude - BVW 227 and http://humanneuro.physiol.umu.se/GW/4mp3/Komm%20Jesu%20Komm%205.mp3'>Komm, Jesu Komm - BVW 229, from Umeå Akademiska Kör. * (Hundreds) of MIDI files at Kunst der Fuge (to be listened and/or saved) and Classical MIDI Connection (to be listened only) * * MP3s and videos of Bach arrangements for electric bass by Dave Grossman * Works by J. S. Bach MP3 at Magnatune * Cantata "Wachet auf, ruft uns die Stimme" BWV 140 MP3 * Performances of works by Johann Sebastian Bach in MIDI and MP3 formats at Logos Virtual Library * mostly organ works by Bach played on virtual instruments * Free recordings of the Brandenburg Concertos in MP3 and FLAC provided by Czech Radio (see FLAC)

* Bach manuscripts - video lectures by Christoph Wolff on the Bach family's hidden manuscripts archive

* Faces of Bach - Site discussing the portraits of J. S. Bach. * Bach Tuning * An article on Bach's purported 'tuning pattern' from his manuscript of The Well Tempered Clavier * * *Bach on the bus - tour at signandsight.com *Virtuosi, Mystics - Biber, Bach * OVPP One Voice Per Part

*The American Bach Society *Bach Concert Series, Baltimore, Maryland *Oregon Bach Festival *Bach Festival at Baldwin-Wallace College - Oldest collegiate Bach Festival in the United States *Bach Festival Swidnitz, (Poland) Take place annually in July.

Johann Sebastian Bach