# Johann Sebastian Bach

Johann Sebastian Bach (31 March [O.S. 21 March] 1685 – 28 July 1750) was a German composer and musician of the late Baroque period. He is known for his prolific output across a variety of instruments and forms, including the orchestral Brandenburg Concertos; solo instrumental works such as the cello suites and sonatas and partitas for solo violin; keyboard works such as the Goldberg Variations and The Well-Tempered Clavier; organ works such as the Schübler Chorales and the Toccata and Fugue in D minor; and choral works such as the St Matthew Passion and the Mass in B minor. Since the 19th-century Bach Revival, he has been widely regarded as one of the greatest composers in the history of Western music.
The Bach family already had several composers when Johann Sebastian was born as the last child of a city musician, Johann Ambrosius, in Eisenach. After being orphaned at age 10, he lived for five years with his eldest brother, Johann Christoph, then continued his musical education in Lüneburg. In 1703 he returned to Thuringia, working as a musician for Protestant churches in Arnstadt and Mühlhausen, and for longer periods at courts in Weimar, where he expanded his organ repertory, and Köthen, where he was mostly engaged with chamber music. In 1723 he was hired as Thomaskantor (cantor at St Thomas's) in Leipzig. There he composed music for the principal Lutheran churches of the city and its university's student ensemble Collegium Musicum. In 1726 he began publishing his keyboard and organ music. In Leipzig, as had happened during some of his earlier positions, he had difficult relations with his employer. This situation was somewhat remedied when his sovereign, Augustus III of Poland, granted him the title of court composer in 1736. In the last decades of his life, Bach reworked and extended many of his earlier compositions. He died of complications after a botched eye surgery in 1750 at the age of 65.
Bach enriched established German styles through his mastery of counterpoint, harmonic and motivic organisation, and his adaptation of rhythms, forms, and textures from abroad, particularly Italy and France. His compositions include hundreds of cantatas, both sacred and secular. He composed Latin church music, Passions, oratorios, and motets. He often adopted Lutheran hymns, not only in his larger vocal works but, for instance, also in his four-part chorales and his sacred songs. Bach wrote extensively for organ and for other keyboard instruments. He composed concertos, for instance for violin and for harpsichord, and suites, as chamber music as well as for orchestra. Many of his works use contrapuntal techniques like canon and fugue.
In the 18th century Bach was primarily known as an organist, while his keyboard music, such as The Well-Tempered Clavier, was appreciated for its didactic qualities. The 19th century saw the publication of some significant Bach biographies, and by the end of that century all of his known music had been printed. Dissemination of scholarship on the composer continued through periodicals (and later also websites) exclusively devoted to him and other publications such as the Bach-Werke-Verzeichnis (BWV, a numbered catalogue of his works) and new critical editions of his compositions. His music was further popularised through a multitude of arrangements, including the Air on the G String and "Jesu, Joy of Man's Desiring", and of recordings such as three different box sets with complete performances of his oeuvre marking the 250th anniversary of his death.

## Life
### Childhood (1685–1703)

Johann Sebastian Bach was born in Eisenach, the capital of the duchy of Saxe-Eisenach, in present-day Germany, on 21 March 1685 O.S. (31 March 1685 N.S.). He was the eighth and youngest child of Johann Ambrosius Bach, the director of the town musicians, and Maria Elisabeth Lämmerhirt. His father likely taught him violin and basic music theory. His uncles were all professional musicians who worked as church organists, court chamber musicians, and composers. One uncle, Johann Christoph Bach, introduced him to the organ, and an older second cousin, Johann Ludwig Bach, was a well-known composer and violinist.
Bach's mother died in 1694, and his father died eight months later. The 10-year-old Bach moved in with his eldest brother, Johann Christoph Bach, the organist at St. Michael's Church in Ohrdruf, Saxe-Gotha-Altenburg. There he studied, performed, and copied music, including his brother's, despite being forbidden to do so because scores were so valuable and private and blank ledger paper was costly. He received valuable teaching from his brother, who instructed him on the clavichord. Johann Christoph exposed him to the works of great composers of the day, including South Germans such as Johann Caspar Kerll, Johann Jakob Froberger, and Johann Pachelbel (under whom Johann Christoph had studied); North Germans; Frenchmen such as Jean-Baptiste Lully, Louis Marchand, and Marin Marais; and the Italian Girolamo Frescobaldi. He learned theology, Latin and Greek at the local gymnasium.
By 3 April 1700, Bach and his school friend Georg Erdmann—who was two years older than Bach—studied at St. Michael's School in Lüneburg, some two weeks' travel north of Ohrdruf. Their journey was probably undertaken mostly on foot. His two years there were critical in exposing Bach to a broader range of European culture. In addition to singing in the choir, he played the school's three-manual organ and harpsichords. He also came into contact with sons of aristocrats from northern Germany who had been sent to the nearby Ritter-Academie to prepare for careers in other disciplines.

### Weimar, Arnstadt, and Mühlhausen (1703–1708)

In January 1703, shortly after graduating from St. Michael's and being turned down for the post of organist at Sangerhausen, Bach was appointed court musician in the chapel of Duke Johann Ernst III in Weimar. His role there is unclear, but it probably included menial, non-musical duties. During his seven-month tenure at Weimar, his reputation as a keyboardist spread so widely that he was invited to inspect the new organ and give the inaugural recital at the New Church (now Bach Church) in Arnstadt, about 30 kilometres (19 mi) southwest of Weimar. On 14 August 1703, he became the organist at the New Church, with light duties, a relatively generous salary, and a new organ tuned in a temperament that allowed music written in a wider range of keys to be played.
Despite strong family connections and a musically enthusiastic employer, tension built up between Bach and the authorities after several years in the post. Bach felt discontented by the calibre of musicians he was collaborating with. He called one of them, Geyersbach, a "Zippel Fagottist" (weenie bassoonist). Late one evening, Geyersbach went after Bach with a stick. Bach filed a complaint against Geyersbach with the authorities. They acquitted Geyersbach with a minor reprimand and ordered Bach to be more moderate about the musical qualities he expected from his students. Some months later, Bach upset his employer with a prolonged absence from Arnstadt: after obtaining leave for four weeks, he was absent for around four months in 1705–1706 to take lessons from the organist and composer Johann Adam Reincken and to hear him and Dieterich Buxtehude play in the northern city of Lübeck. The visit to Buxtehude and Reincken involved a 450-kilometre (280 mi) journey each way, reportedly on foot. Buxtehude probably introduced Bach to his friend Reincken so that he could learn from his compositional technique (especially his mastery of fugue), his organ playing and his skills with improvisation. Bach knew Reincken's music very well; he copied Reincken's monumental An Wasserflüssen Babylon when he was 15 years old. Bach later wrote several other works on the same theme. When Bach revisited Reincken in 1720 and showed him his improvisatory skills on the organ, Reincken reportedly remarked: "I thought that this art was dead, but I see that it lives in you."
In 1706, Bach applied for a post as organist at the Blasius Church in Mühlhausen. As part of his application, he had a cantata performed on Easter, 24 April 1707, likely an early version of his Christ lag in Todes Banden. Bach's application was accepted a month later, and he took up the post in July. The position included significantly higher remuneration, improved conditions, and a better choir. Four months after arriving at Mühlhausen, Bach married Maria Barbara Bach, his second cousin. Bach convinced the church and town government at Mühlhausen to fund an expensive renovation of the organ at the Blasius Church. In 1708, Bach wrote Gott ist mein König, a festive cantata for the inauguration of the new council, which was published at the council's expense. This was to be the first and only cantata by Bach published during his lifetime.

### Return to Weimar (1708–1717)

Bach left Mühlhausen in 1708, returning to Weimar this time as organist and from 1714 Konzertmeister (director of music) at the ducal court, where he could work with a large, well-funded contingent of professional musicians. Bach and his wife moved into a house near the ducal palace. Later that year, their first child, Catharina Dorothea, was born, and Maria Barbara's elder, unmarried sister joined them. She remained to help run the household until she died in 1729. Three sons were also born in Weimar: Wilhelm Friedemann, Carl Philipp Emanuel, and Johann Gottfried Bernhard. Johann Sebastian and Maria Barbara had three more children—twins born in 1713 and a single birth; none survived past their first birthday.
Bach's time in Weimar began a sustained period of composing keyboard and orchestral works. He attained the proficiency and confidence to extend the prevailing structures and include influences from abroad. He learned to write dramatic openings and employ the dynamic rhythms and harmonic schemes found in the music of Italians such as Vivaldi, Corelli, and Torelli. Bach absorbed these stylistic aspects to a certain extent by transcribing Vivaldi's string and wind concertos for harpsichord and organ; many of these transcribed works are still regularly performed. Bach was particularly attracted to the Italian style, in which one or more solo instruments alternate section-by-section with the full orchestra throughout a movement.
In Weimar, Bach continued to play and compose for the organ and perform concert music with the duke's ensemble. He also began to write the preludes and fugues that were later assembled into his monumental work The Well-Tempered Clavier ("clavier" meaning clavichord or harpsichord), consisting of two books, each containing 24 preludes and fugues in every major and minor key. In Weimar Bach also started work on the Little Organ Book, containing traditional Lutheran chorale tunes set in complex textures. In 1713, Bach was offered a post in Halle when he advised the authorities during a renovation by Christoph Cuntzius of the main organ in the west gallery of the Market Church of Our Dear Lady.
In the spring of 1714, Bach was promoted to Konzertmeister, an honour that entailed performing a church cantata monthly in the castle church. The first three cantatas in the new series Bach composed in Weimar were Himmelskönig, sei willkommen, BWV 182, for Palm Sunday, which coincided with the Annunciation that year; Weinen, Klagen, Sorgen, Zagen, BWV 12, for Jubilate Sunday; and Erschallet, ihr Lieder, erklinget, ihr Saiten! BWV 172 for Pentecost. Bach's first Christmas cantata, Christen, ätzet diesen Tag, BWV 63, premiered in 1714 or 1715.
In 1717, Bach fell out of favour in Weimar and, according to a translation of the court secretary's report, was jailed for almost a month before being unfavorably dismissed: "On November 6, [1717,] the quondam [former] concertmaster and organist Bach was confined to the County Judge's place of detention for too stubbornly forcing the issue of his dismissal and finally on December 2 was freed from arrest with notice of his unfavorable discharge."

### Köthen (1717–1723)

Leopold, Prince of Anhalt-Köthen, hired Bach to serve as his Kapellmeister (director of music) in 1717. Himself a musician, Leopold appreciated Bach's talents, paid him well, and gave him considerable latitude in composing and performing. Leopold was a Calvinist and did not use elaborate music in his worship; accordingly, most of Bach's work from this period is secular, including the orchestral suites, cello suites, sonatas and partitas for solo violin, and the Brandenburg Concertos. Bach also composed secular cantatas for the court, such as Die Zeit, die Tag und Jahre macht, BWV 134a.
Despite being born in the same year and only about 130 kilometres (80 mi) apart, Bach and Handel never met. In 1719, Bach made the 35-kilometre (22 mi) journey from Köthen to Halle with the intention to meet Handel, but Handel had left town. In 1730, Bach's oldest son, Wilhelm Friedemann, travelled to Halle to invite Handel to visit the Bach family in Leipzig, but the visit did not take place.
On 7 July 1720, while Bach was away in Carlsbad with Leopold, his wife, Maria Barbara Bach, suddenly died. The next year, he met Anna Magdalena Wilcke, a young, gifted soprano 16 years his junior, who performed at the court in Köthen; they married on 3 December 1721. Together they had 13 children, six of whom survived into adulthood: Gottfried Heinrich; Elisabeth Juliane Friederica (1726–1781); Johann Christoph Friedrich and Johann Christian, who both, especially Johann Christian, became significant musicians; Johanna Carolina (1737–1781); and Regina Susanna (1742–1809).

### Leipzig (1723–1750)

In 1723, Bach was appointed Thomaskantor director of church music in Leipzig. He had to direct the St. Thomas School and provide four churches with music, the St. Thomas Church, the St. Nicholas Church, and to a lesser extent, the New Church and St. Peter's Church. This was "the leading cantorate in Protestant Germany", located in the mercantile city in the Electorate of Saxony, which he held for 27 years, until his death. During that time he gained further prestige through honorary appointments at the courts of Köthen and Weissenfels, as well as that of the Elector Frederick Augustus (who was also King of Poland) in Dresden. Bach frequently disagreed with his employer, Leipzig's city council, which he regarded as "penny-pinching".

#### Appointment in Leipzig

Johann Kuhnau had been Thomaskantor in Leipzig from 1701 until his death on 5 June 1722. Bach had visited Leipzig during Kuhnau's tenure: in 1714, he attended the service at the St. Thomas Church on the first Sunday of Advent, and in 1717 he had tested the organ of the St. Paul's Church. In 1716, Bach and Kuhnau met on the occasion of the testing and inauguration of an organ in Halle.
The position was offered to Bach only after it had been offered to Georg Philipp Telemann and then to Christoph Graupner, both of whom chose to stay where they were—Telemann in Hamburg and Graupner in Darmstadt—after using the Leipzig offer to negotiate better terms of employment.
Bach was required to instruct the Thomasschule students in singing and provide church music for the main churches in Leipzig. He was also assigned to teach Latin but was allowed to employ four "prefects" (deputies) to do this instead. The prefects also aided with musical instruction. A cantata was required for the church services on Sundays and additional church holidays during the liturgical year.

#### Cantata cycle years (1723–1729)

Bach usually led performances of his cantatas, most composed within three years of his relocation to Leipzig. He assumed the office of Thomaskantor on 30 May 1723, presenting the first new cantata, Die Elenden sollen essen, BWV 75, in the St. Nicholas Church on the first Sunday after Trinity. Bach collected his cantatas in annual cycles. Five are mentioned in obituaries, and three are extant. Of the more than 300 cantatas he composed in Leipzig, over 100 have been lost to posterity. Most of these works expound on the Gospel readings prescribed for every Sunday and feast day in the Lutheran year. Bach started a second annual cycle on the first Sunday after the Trinity of 1724 and composed only chorale cantatas, each based on a single church hymn. These include O Ewigkeit, du Donnerwort, BWV 20, Wachet auf, ruft uns die Stimme, BWV 140, Nun komm, der Heiden Heiland, BWV 62, and Wie schön leuchtet der Morgenstern, BWV 1.
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; probably for this purpose, and for in-school training, he wrote at least six motets. As part of his regular church work, he performed other composers' motets, which served as formal models for his own.
Bach's predecessor as cantor, Johann Kuhnau, had also been music director for the St. Paul's Church, the church of Leipzig University. But when Bach was installed as cantor in 1723, he was put in charge only of music for festal (church holiday) services at St. Paul's Church; his petition to also provide music for regular Sunday services there (for a corresponding salary increase) went all the way to the Elector but was denied. In 1725, Bach "lost interest" in working even for festal services at St. Paul's Church and decided to appear there only on "special occasions". The St. Paul's Church had a much better and newer (1716) organ than the St. Thomas Church or the St. Nicholas Church. Bach was not required to play any organ in his official duties, but it is believed he liked to play on the St. Paul's Church organ for his own pleasure.
Bach broadened his composing and performing beyond the liturgy by taking over, in March 1729, the directorship of the Collegium Musicum, a secular performance ensemble Telemann started. This was one of the dozens of private societies in the major German-speaking cities established by musically active university students; they had become increasingly important 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". Every week, the Collegium Musicum gave two-hour performances, in winter at the Café Zimmermann, a coffeehouse on Catherine Street off the main market square, and in summer in the proprietor's outdoor coffee garden just outside the town walls, near the East Gate. The concerts, all free of charge, ended with Gottfried Zimmermann's death in 1741. Apart from showcasing his earlier orchestral repertoire, such as the Brandenburg Concertos and orchestral suites, many of Bach's newly composed or reworked pieces were performed for these venues, including parts of his Clavier-Übung (Keyboard Practice), his violin and keyboard concertos, and the Coffee Cantata.

#### Middle years of the Leipzig period (1730–1739)

In 1733, Bach composed a Kyrie–Gloria Mass in B minor that he later incorporated in his Mass in B minor. He presented the manuscript to the Elector in a successful bid to persuade the prince to give him the title of Court Composer. He later extended this work into a full mass by adding a Credo, Sanctus, and Agnus Dei, the music for which was partly based on his own cantatas and partly original. Bach's appointment as Court Composer was an element of his long-term struggle to achieve greater bargaining power with the Leipzig council. Between 1737 and 1739, Bach's former pupil Carl Gotthelf Gerlach held the directorship of the Collegium Musicum.
In 1735, Bach started preparing his first organ music publication, which was printed as the third Clavier-Übung in 1739. From around that year he started to compile and compose the set of preludes and fugues for harpsichord that became the second book of The Well-Tempered Clavier. He received the title of "Royal Court Composer" from Augustus III in 1736.

#### Final years and death (1740–1750)

From 1740 to 1748 Bach copied, transcribed, expanded or programmed music in an older polyphonic style (stile antico) by, among others, Palestrina (BNB I/P/2), Kerll (BWV 241), Torri (BWV Anh. 30), Bassani (BWV 1081), Gasparini (Missa Canonica), and Caldara (BWV 1082). Bach's style shifted in the last decade of his life, showing an increased integration of polyphonic structures and canons and other elements of the stile antico. His fourth and last Clavier-Übung volume, the Goldberg Variations for two-manual harpsichord, contained nine canons and was published in 1741. During this period, Bach also continued to adapt music of contemporaries such as Handel (BNB I/K/2) and Stölzel (BWV 200), and gave many of his own earlier compositions, such as the St Matthew and St John Passions and the Great Eighteen Chorale Preludes, their final revisions. He also programmed and adapted music by composers of a younger generation, including Pergolesi (BWV 1083), and his own students, such as Goldberg (BNB I/G/2).
In 1746 Bach was preparing to enter Lorenz Christoph Mizler's Society of Musical Sciences [de]. To be admitted, he had to submit a composition. He chose his Canonic Variations on "Vom Himmel hoch da komm' ich her", and a portrait painted by Elias Gottlob Haussmann that featured Bach's Canon triplex á 6 Voc. In May 1747, Bach visited the court of King Frederick II of Prussia in Potsdam. The king played a theme for Bach and challenged him to improvise a fugue based on it. Bach obliged, playing a three-part fugue on one of Frederick's fortepianos, a new type of instrument at the time. Upon his return to Leipzig he composed a set of fugues and canons and a trio sonata based on the Thema Regium ("king's theme"). Within a few weeks this music was published as The Musical Offering and dedicated to Frederick. The Schübler Chorales, a set of six chorale preludes transcribed from cantata movements Bach had written two decades earlier, were published within a year. Around the same time, the set of five canonic variations Bach had submitted when entering Mizler's society in 1747 were also printed.
Two large-scale compositions occupied a central place in Bach's last years. Beginning around 1742, he wrote and revised the various canons and fugues of The Art of Fugue, which he continued to prepare for publication until shortly before his death. After extracting a cantata, BWV 191 from his 1733 Kyrie-Gloria Mass for the Dresden court in the mid-1740s, Bach expanded that setting into his Mass in B minor in the last years of his life. The complete mass was not performed during his lifetime. It is considered among the greatest choral works in history.
In January 1749, Bach's daughter Elisabeth Juliane Friederica married his pupil Johann Christoph Altnickol. Bach's health was declining. On 2 June, Heinrich von Brühl wrote to one of the Leipzig burgomasters to request that his music director, Gottlob Harrer, fill the Thomaskantor and Director musices posts "upon the eventual ... decease of Mr. Bach". Becoming blind, Bach underwent eye surgery in March 1750 and again in April by the British eye surgeon John Taylor, a man widely understood today as a charlatan and believed to have blinded hundreds of people. Bach died on 28 July 1750 from complications due to the unsuccessful treatment.
An inventory drawn up a few months after Bach's death shows that his estate included five harpsichords, two lute-harpsichords, three violins, three violas, two cellos, a viola da gamba, a lute, a spinet, and 52 "sacred books", including works by Martin Luther and Josephus. C.P.E. Bach saw to it that The Art of Fugue, though unfinished, was published in 1751. Together with one of J.S. Bach's former students, Johann Friedrich Agricola, C.P.E. Bach also wrote the obituary ("Nekrolog"), which was published in Mizler's Musikalische Bibliothek [de], a periodical journal produced by the Society of Musical Sciences, in 1754.

## Musical style

From an early age, Bach studied the works of his musical contemporaries of the Baroque period and those of earlier generations, and those influences are reflected in his music. Like his contemporaries Handel, Telemann, and Vivaldi, Bach composed concertos, suites, recitatives, da capo arias, and four-part choral music, and employed basso continuo. His music is harmonically more innovative than his peers', employing surprisingly dissonant chords and progressions, often extensively exploring harmonic possibilities within one piece.
Bach's hundreds of sacred works are usually seen as manifesting not just his craft but also a deep faith in God. He had taught Luther's Small Catechism as the Thomaskantor in Leipzig, and some of his pieces represent it. The Lutheran chorale was the basis of much of his work. In elaborating these hymns into his chorale preludes, he wrote more cogent and tightly integrated works than most, even when they were massive and lengthy. The large-scale structure of every major Bach sacred vocal work is evidence of subtle, elaborate planning to create religiously and musically powerful expression. For example, the St Matthew Passion, like other works of its kind, illustrated the Passion with Bible text reflected in recitatives, arias, choruses, and chorales, but in crafting this work, Bach created an overall experience that has been found over the intervening centuries to be both musically thrilling and spiritually profound.
Bach published or carefully compiled in manuscript many collections of pieces that explored the range of artistic and technical possibilities inherent in almost every genre of his time except opera. For example, The Well-Tempered Clavier comprises two books, each of which presents a prelude and fugue in every major and minor key, displaying a dizzying variety of structural, contrapuntal and fugal techniques.

### Four-part harmony

Four-part harmony predates Bach, but he lived during a time when modal music in Western tradition was largely supplanted by the tonal system. In this system a piece of music progresses from one chord to the next according to certain rules, with each chord characterised by four notes. The principles of four-part harmony are found not only in Bach's four-part choral music; he also prescribes it for instance in figured bass accompaniment. The new system was at the core of Bach's style, and his compositions are to a large extent considered to have laid down the rules for the evolving scheme that dominated musical expression in the next centuries. Some examples of this characteristic of Bach's style and its influence:
* When in the 1740s Bach staged his arrangement of Pergolesi's Stabat Mater, he upgraded the viola part (which in the original composition plays in unison with the bass part) to fill in the harmony, thus adapting the composition to four-part harmony.
* When, starting in the 19th century in Russia, there was a discussion about the authenticity of four-part court chant settings compared to earlier Russian traditions, Bach's four-part chorale settings, such as those ending his Chorale cantatas, were considered foreign-influenced models, but such influence was deemed unavoidable.
Bach's insistence on the tonal system and contribution to shaping it did not imply he was less at ease with the older modal system and the genres associated with it: more than his contemporaries (who had "moved on" to the tonal system without much exception), Bach often returned to the then-antiquated modes and genres. His Chromatic Fantasia and Fugue, emulating the chromatic fantasia genre used by earlier composers such as Dowland and Sweelinck in D dorian mode (comparable to D minor in the tonal system), is an example.

### Modulation

Modulation, or changing key in the course of a piece, is another style characteristic where Bach goes beyond the norm in his time. Baroque instruments vastly limited modulation possibilities: keyboard instruments, before a workable system of temperament, limited the keys that could be modulated to, and wind instruments, especially brass instruments such as trumpets and horns, about a century before they were fitted with valves, were tied to the key of their tuning. Bach pushed the limits: he added "strange tones" in his organ playing, confusing the singers, according to an indictment he had to face in Arnstadt, and Louis Marchand, another early experimenter with modulation, seems to have avoided confrontation with Bach because the latter went further than anyone had done before. In the "Suscepit Israel" of his 1723 Magnificat, he had the trumpets in E-flat play a melody in the enharmonic scale of C minor.
The major development in Bach's time to which he contributed in no small way was a temperament for keyboard instruments that allowed their use in every key (12 major and 12 minor) and also modulation without retuning. His Capriccio on the departure of a beloved brother, a very early work, showed a gusto for modulation unlike any contemporary work it has been compared to, but the full expansion came with the Well-Tempered Clavier, using all keys, which Bach apparently had been developing since around 1720, the Klavierbüchlein für Wilhelm Friedemann Bach being one of its earliest examples.

### Ornamentation

The second page of the Klavierbüchlein für Wilhelm Friedemann Bach is an ornament notation and performance guide that Bach wrote for his eldest son when he was nine years old. Bach was generally quite specific on ornamentation in his compositions (in his time, much ornamentation was not written out by composers but rather considered a liberty of the performer), and his ornamentation was often quite elaborate. For instance, the "Aria" of the Goldberg Variations has rich ornamentation in nearly every measure. Bach's approach to ornamentation can also be seen in a keyboard arrangement he made of Marcello's Oboe Concerto: he added explicit ornamentation, which centuries later is still played.
Although Bach wrote no operas, he was not averse to the genre or its ornamented vocal style. In church music, Italian composers had imitated the operatic vocal style in genres such as the Neapolitan mass. In Protestant surroundings, there was more reluctance to adopt such a style for liturgical music. Kuhnau had notoriously shunned opera and Italian virtuoso vocal music. Bach was less moved. After a performance of his St Matthew Passion, someone said it all sounded much like opera.

### Continuo instruments solos

In concerted playing in Bach's time, the basso continuo, consisting of instruments such as organ, viola da gamba, or harpsichord, usually had the role of accompaniment, providing a piece's harmonic and rhythmic foundation. Beginning in the 1720s, Bach had the organ play concertante (i.e., as a soloist) with the orchestra in instrumental cantata movements, a decade before Handel published his first organ concertos. Apart from the 5th Brandenburg Concerto and the Triple Concerto, which already had harpsichord soloists in the 1720s, Bach wrote and arranged his harpsichord concertos in the 1730s, and in his sonatas for viola da gamba and harpsichord neither instrument plays a continuo part: they are treated as equal soloists, far beyond the figured bass. In this way, Bach played a key role in the development of genres such as the keyboard concerto.

### Instrumentation

Bach wrote virtuoso music for specific instruments as well as music independent of instrumentation. For instance, the sonatas and partitas for solo violin are considered the pinnacle of what has been written for violin, within reach of only accomplished players. The music fits the instrument, using the full gamut of its possibilities and requiring virtuosity but without bravura. Notwithstanding that the music and the instrument seem inseparable, Bach transcribed some pieces in this collection for other instruments. Similarly, the virtuoso cello suites seem tailored to the instrument, the best of what is offered for it, but Bach arranged one of the suites for lute. The same applies to much of his most virtuoso keyboard music. Bach exploited an instrument's capacities to the fullest while keeping the core of the music independent of the instrument on which it is performed.
In this sense, it is no surprise that Bach's music is easily and often performed on instruments it was not written for, that it is transcribed so often, and that his melodies turn up in unexpected places, such as jazz music. Apart from this, Bach left several compositions without specified instrumentation: the canons BWV 1072–1078 are in that category, as is the bulk of the Musical Offering and the Art of Fugue.

### Counterpoint

Another characteristic of Bach's style is his extensive use of counterpoint, as opposed to the homophony used in his four-part chorale settings, for example. Bach's canons, and especially his fugues, are the most characteristic of this style, which he did not invent but contributed to so fundamentally that to a large extent he defined it. Fugues are as characteristic of Bach's style as, for instance, sonata form is of the composers of the Classical period.
These strictly contrapuntal compositions, and most of Bach's music in general, are characterised by distinct melodic lines for each voice, where the chords formed by the notes sounding at a given point follow the rules of four-part harmony. Johann Nikolaus Forkel, Bach's first biographer, gives this description of this feature of Bach's music, which sets it apart from most other music:
   If the language of music is merely the utterance of a melodic line, a simple sequence of musical notes, it can justly be accused of poverty. The addition of a Bass puts it upon a harmonic foundation and clarifies it but defines rather than gives it added richness. A melody so accompanied—even though all the notes are not those of the true Bass—or treated with simple embellishments in the upper parts or with simple chords used to be called "homophony". But it is a very different thing when two melodies are so interwoven that they converse together like two persons upon a footing of pleasant equality. In the first case, the accompaniment is subordinate and serves merely to support the first or principal part. In the second case, the two parts are not similarly related. New melodic combinations spring from their interweaving, out of which new forms of musical expression emerge. Suppose more parts are interwoven in the same free and independent manner. In that case, the apparatus of language is correspondingly enlarged and becomes practically inexhaustible if, in addition, varieties of form and rhythm are introduced. Hence, harmony becomes no longer a mere accompaniment of melody but rather a potent agency for augmenting the richness and expressiveness of musical conversation. To serve that end, a simple accompaniment will not suffice. True harmony is the interweaving of several melodies, which emerge now in the upper, now in the middle, and now in the lower parts.
   From 1720, when he was thirty-five until he died in 1750, Bach's harmony consists of this melodic interweaving of independent melodies, so perfect in their union that each part seems to constitute the true melody. Herein, Bach excels all the composers in the world. At least, I have found no one to equal him in music known to me. Even in his four-part writing, we can, not infrequently, leave out the upper and lower parts and still find the middle parts harmonious and agreeable.

### Structure and lyrics

Bach devoted more attention than his contemporaries to his compositions' structure. This can be seen in minor adjustments he made when adapting someone else's work, such as his earliest version of the "Keiser" St Mark Passion, where he enhances scene transitions, and in the architecture of his own work, such as his Magnificat and Leipzig Passions. In his last years, Bach revised several of his compositions. Often, recasting such previously composed music in an enhanced structure was the most salient change, as in the Mass in B minor. Bach's known preoccupation with structure led (peaking around the 1970s) to various numerological analyses of his compositions, although many of these were later rejected, especially those that wandered into symbolism-ridden hermeneutics.
The librettos, or lyrics, of his vocal compositions played an essential role for Bach. He sought collaboration with various text authors for his cantatas and major vocal compositions, possibly writing or adapting such texts himself to make them fit the structure of the composition when he could not rely on the talents of other text authors. His collaboration with Picander for the St Matthew Passion libretto is best known, but there was a similar process in achieving a multi-layered structure for his St John Passion libretto a few years earlier.

## Compositions

In 1950, Wolfgang Schmieder published a thematic catalogue of Bach's compositions called the Bach-Werke-Verzeichnis (Bach Works Catalogue). Schmieder largely followed the Bach-Gesellschaft-Ausgabe, a comprehensive edition of the composer's works that was produced between 1850 and 1900. The first edition of the catalogue listed 1,080 surviving compositions indisputably composed by Bach.
Original Bach-Werke-Verzeichnis (Bach Works Catalogue) :
| BWV Range | Compositions |
| BWV 1–224 | Cantatas |
| BWV 225–231 | Motets |
| BWV 232–243 | Liturgical compositions in Latin |
| BWV 244–249 | Passions and oratorios |
| BWV 250–438 | Four-part chorales |
| BWV 439–524 | Small vocal works |
| BWV 525–771 | Organ compositions |
| BWV 772–994 | Other keyboard works |
| BWV 995–1000 | Lute compositions |
| BWV 1001–1040 | Other chamber music |
| BWV 1041–1071 | Orchestral music |
| BWV 1072–1078 | Canons |
| BWV 1079–1080 | Late contrapuntal works |
BWV 1081–1126 were added to the catalogue in the second half of the 20th century, and BWV 1127 and higher are 21st-century additions.

### Passions and oratorios

Bach composed Passions for Good Friday services and oratorios such as the Christmas Oratorio, which is a set of six cantatas for use in the liturgical season of Christmas. Shorter oratorios include the Easter Oratorio and the Ascension Oratorio. With its double choir and orchestra, the St Matthew Passion is one of Bach's most extended works. The St John Passion was the first passion Bach composed during his tenure as Thomaskantor in Leipzig.

### Cantatas

According to his obituary, Bach would have composed five year-cycles of sacred cantatas and additional church cantatas for weddings and funerals. Approximately 200 of these sacred works are extant, an estimated two-thirds of the total number of church cantatas he composed. The Bach Digital website lists 50 known secular cantatas by the composer, about half of which are extant or largely reconstructable.

#### Church cantatas

Bach's cantatas vary greatly in form and instrumentation. Many consist of a large opening chorus followed by one or more recitative-aria pairs for soloists (or duets) and a concluding chorale. The melody of the concluding chorale often appears as a cantus firmus in the opening movement.
Bach's earliest cantatas date from his years in Arnstadt and Mühlhausen. The earliest surviving work in the genre is Nach dir, Herr, verlanget mich, BWV 150. Overall, the extant early works show remarkable mastery and skill. Many feature an instrumental opening which displays effective use of the limited instrumental forces available to Bach, whether it be in the subdued combination of two recorders and two violas de gamba for BWV 106, or the independent bassoon in BWV 196. Bach's compositional skills also manifest through his daring harmonies and advanced, unprecedented chord progressions. According to Christoph Wolff, Bach's early cantatas are impressive evidence of how the modest means at his disposal did not restrain the composer in the slightest, and they compare favourably with compositions by the most talented composers from the beginning of the 18th century, such as Krieger, Kuhnau or Zachow.
After taking up his office as Thomaskantor in late May 1723, Bach performed a cantata each Sunday and feast day, corresponding to the lectionary readings of the week. His first cantata cycle ran from the first Sunday after Trinity of 1723 to Trinity Sunday the next year. For instance, the Visitation cantata Herz und Mund und Tat und Leben, BWV 147, containing the chorale that is known in English as "Jesu, Joy of Man's Desiring", belongs to this first cycle. The cantata cycle of his second year in Leipzig is called the chorale cantata cycle as it consists mainly of works in the chorale cantata format. His third cantata cycle was developed over several years, followed by the Picander cycle of 1728–29.
Later church cantatas include the chorale cantatas Ein feste Burg ist unser Gott, BWV 80 (final version) and Wachet auf, ruft uns die Stimme, BWV 140. Only the first three Leipzig cycles are more or less completely extant. Apart from his own work, Bach also performed cantatas by Telemann and by his distant relative Johann Ludwig Bach.

#### Secular cantatas

Bach also wrote secular cantatas, for instance for members of the royal Polish and prince-electoral Saxonian families (e.g. Trauer-Ode), or other public or private occasions (e.g. Hunting Cantata). The text of these cantatas was occasionally in dialect (e.g. Peasant Cantata) or Italian (e.g. Amore traditore). Many of the secular cantatas were lost, but for some of them, the text and occasion are known. For instance, when Picander later published their librettos (e.g. BWV Anh. 11–12).
Some of the surviving secular cantatas have a plot involving mythological figures of Greek antiquity (e.g. Der Streit zwischen Phoebus und Pan), and others were almost miniature buffo operas (e.g. Coffee Cantata). Although Bach never expressed any interest in opera, his secular cantatas, or drammi per musica, would have allowed Leipzig audiences, deprived of opera since 1720, to experience musical performances comparable to the royal opera in Dresden. These were not "poor or makeshift substitutes for real opera" but spectacles displaying "full mastery of the dramatic genre and the proper pacing of the dialogues."

### A cappella music

Bach's a cappella music includes motets and chorale harmonisations.

#### Motets

Bach's motets (BWV 225–231) are pieces on sacred themes for choir and continuo, with instruments playing colla parte. Several of them were composed for funerals. The six motets definitely composed by Bach are 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. The motet Sei Lob und Preis mit Ehren (BWV 231) is part of the composite motet Jauchzet dem Herrn, alle Welt (BWV Anh. 160), other parts of which may be based on work by Telemann.

#### Chorale harmonisations

Bach wrote hundreds of four-part harmonisations of Lutheran chorales.

### Church music in Latin

Bach's church music in Latin includes the Magnificat, four Kyrie–Gloria Masses, and the Mass in B minor.

#### Magnificat

The first version of Bach's Magnificat dates from 1723, but the work is best known in its D major version of 1733.

#### Mass in B minor

In 1733, Bach composed a Kyrie–Gloria Mass for the Dresden court. Near the end of his life, around 1748–1749, he expanded this composition into the large-scale Mass in B minor. The work was never performed in full during Bach's lifetime.

### Keyboard music

Bach wrote for organ and for stringed keyboard instruments such as harpsichord, clavichord and lute-harpsichord.

#### Organ works

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). At a young age, he established a reputation for creativity and the 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, whom the young organist visited in Lübeck 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. During his most productive period (1708–1714), he composed about a dozen pairs of preludes and fugues, five toccatas and fugues, and the Orgelbüchlein or "Little Organ Book", an unfinished collection of 46 short chorale preludes that demonstrate compositional techniques in the setting of chorale tunes. After leaving Weimar, Bach wrote less for organ, although some of his best-known works (the six Organ Sonatas, the German Organ Mass in Clavier-Übung III from 1739, and the Great Eighteen Chorale Preludes, revised late in his life) were composed after leaving Weimar. Later in his life, Bach extensively consulted on organ projects, tested new organs, and dedicated playing organs to afternoon recitals. The Canonic Variations on "Vom Himmel hoch da komm' ich her" and the Schübler Chorales are organ works Bach published in the last years of his life.

#### Harpsichord and other stringed keyboard instruments

Bach wrote many works for harpsichord, some of which may also have been played on the clavichord or lute-harpsichord. Some of his more significant works, such as Clavier-Übung II and IV, are intended for a harpsichord with two manuals: performing them on a keyboard instrument with a single manual (like a piano) may present technical difficulties for the crossing of hands.
* The Well-Tempered Clavier, Books 1 and 2 (BWV 846–893). Each book consists of a prelude and fugue in each of the 24 major and minor keys, in chromatic order from C major to B minor (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 utilise more than just a few keys.
* The Inventions and Sinfonias (BWV 772–801). These short two- and three-part contrapuntal works are arranged in the same chromatic order as The Well-Tempered Clavier, omitting certain rarer keys. Bach intended these pieces for instructional purposes.
* Three collections of dance suites: the English Suites (BWV 806–811), French Suites (BWV 812–817), and Partitas for keyboard (Clavier-Übung I, 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 gigue. The French Suites omit preludes but have multiple movements between the sarabande and 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 30 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; every third variation is a canon. These variations move in order from canon at 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. The final variation, instead of being the expected canon at the tenth, is a quodlibet.
* Miscellaneous pieces such as the Overture in the French Style (French Overture, BWV 831) and the Italian Concerto (BWV 971) (published together as Clavier-Übung II), and the Chromatic Fantasia and Fugue (BWV 903).
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).

### Orchestral and chamber music

Bach wrote for single instruments, duets, and small ensembles. Many of his solo works, such as the six sonatas and partitas for violin (BWV 1001–1006) and the six cello suites (BWV 1007–1012), are widely considered to be among the most profound in the repertoire. He wrote sonatas for a solo instrument such as the viola de gamba accompanied by harpsichord or continuo, as well as trio sonatas (two instruments and continuo).
The Musical Offering and The Art of Fugue are late contrapuntal works containing pieces for unspecified or combinations of instruments.

#### Violin concertos

Surviving works in the concerto form include two violin concertos (BWV 1041 in A minor and BWV 1042 in E major) and a concerto for two violins in D minor, BWV 1043, often referred to as Bach's "double concerto".

#### Brandenburg Concertos

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.

#### Keyboard concertos

Bach composed and transcribed concertos for one to four harpsichords. Many of the harpsichord concertos were not original works, but arrangements of his concertos for other instruments are now lost. Several violin, oboe, and flute concertos have been reconstructed from these.

#### Orchestral suites

In addition to concertos, Bach wrote four orchestral suites, each suite being a series of stylised dances for orchestra, preceded by a French overture.

### Copies, arrangements and uncertain attributions

In his early youth, Bach copied pieces by other composers to learn from them. Later, he copied and arranged music for performance or as study material for his pupils. Some of these pieces, like "Bist du bei mir" (copied not by Bach but by Anna Magdalena), became famous before being dissociated with Bach. Bach copied and arranged Italian masters such as Vivaldi (e.g. BWV 1065), Pergolesi (BWV 1083) and Palestrina (Missa Sine nomine), French masters such as François Couperin (BWV Anh. 183), and, closer to home, various German masters including Telemann (e.g. BWV 824=TWV 32:14) and Handel (arias from Brockes Passion), and music from members of his own family. He also often copied and arranged his own music (e.g. movements from cantatas for his short masses BWV 233–236), as his music was likewise copied and arranged by others. Some of these arrangements, like the late 19th-century "Air on the G String", helped to popularise Bach's music.
Sometimes, "who copied whom" is not clear. For instance, Forkel mentions a Mass for double chorus among the works composed by Bach. The work was published and performed in the early 19th century. Although a score partially in Bach's handwriting exists, the work was later considered spurious. In 1950, the design of the Bach-Werke-Verzeichnis was to keep such works out of the main catalogue: if there was a strong association with Bach they could be listed in its appendix (German: Anhang, abbreviated as Anh.). Thus, for instance, the aforementioned Mass for double chorus became BWV Anh. 167. But this was far from the end of the attribution issues. For instance, Schlage doch, gewünschte Stunde, BWV 53, was later attributed to Melchior Hoffmann. For other works, Bach's authorship was put in doubt without a generally accepted answer to the question of whether or not he composed it: the best-known organ composition in the BWV catalogue, the Toccata and Fugue in D minor, BWV 565, was indicated as one of these uncertain works in the late 20th century.

## Reception

In the 18th century, Bach's music was appreciated mostly by distinguished connoisseurs. The 19th century started with the publication of the first biography of Bach and ended with the Bach Gesellschaft's completion and publication of all his known works. Starting with the Bach Revival, he began to be regarded as one of the greatest composers, a reputation he has maintained. The BACH motif, which Bach occasionally used in his compositions, has been used in dozens of tributes to him since the 19th century.

### 18th century

In his own time, Bach was highly regarded by his colleagues, but his reputation outside this small circle of connoisseurs was due not to his compositions (which had an extremely narrow circulation), but to his virtuosic abilities. Nevertheless, during his life, Bach received public recognition, such as the title of court composer by Augustus III of Poland and the appreciation he was shown by Frederick the Great and Hermann Karl von Keyserling. This appreciation contrasted with the humiliations he faced, for instance, in Leipzig. Bach also had detractors in the contemporary press (Johann Adolf Scheibe suggested he write less complex music) and supporters, such as Johann Mattheson and Lorenz Christoph Mizler.
After his death, Bach's reputation as a composer initially declined: his work was regarded as old-fashioned compared to the emerging galant style. He was remembered more as a virtuoso organ player and a teacher. The bulk of the music printed during his lifetime, at least the remembered parts, was for organ or harpsichord. Thus his reputation as a composer was initially mostly limited to his keyboard music, which was relatively limited in its value to music education.
Bach's surviving family members, who inherited many of his manuscripts, were not all equally concerned with preserving them, leading to considerable losses. Carl Philipp Emanuel, his second-eldest son, was most active in safeguarding his father's legacy: he co-authored his father's obituary, contributed to the publication of his four-part chorales, staged some of his works, and helped preserve the bulk of his previously unpublished work. Wilhelm Friedemann, the eldest son, performed several of his father's cantatas in Halle, but after becoming unemployed sold part of the large collection of his father's works he owned. Several students of the old master, such as his son-in-law Johann Christoph Altnickol, Johann Friedrich Agricola, Johann Kirnberger, and Johann Ludwig Krebs, contributed to the dissemination of his legacy. The early devotees were not all musicians; for example, in Berlin, Daniel Itzig, a high official of Frederick the Great's court, venerated Bach. His eldest daughters took lessons from Kirnberger and their sister Sara from Wilhelm Friedemann Bach, who was in Berlin from 1774 to 1784. Sara Itzig Levy became an avid collector of work by J.S. Bach and his sons and was a "patron" of C.P.E. Bach.
While Bach was in Leipzig, performances of his church music were limited to some of his motets, and, under cantor Doles, some of his Passions. A new generation of Bach aficionados emerged who studiously collected and copied his music, including some of his large-scale works such as the Mass in B minor, and performed it privately. One was Gottfried van Swieten, a high-ranking Austrian official who was instrumental in passing Bach's legacy on to the composers of the Viennese school. Haydn owned manuscript copies of The Well-Tempered Clavier and the Mass in B minor and was influenced by Bach's music. Mozart owned a copy of one of Bach's motets, transcribed some of his instrumental works (K. 404a, 405), and wrote contrapuntal music influenced by his style. Beethoven played the entire Well-Tempered Clavier by the time he was 11 and described Bach as Urvater der Harmonie (progenitor of harmony).

### 19th century

In 1802, Johann Nikolaus Forkel published Johann Sebastian Bach: His Life, Art, and Work, the first Bach biography, dedicated to van Swieten. In 1805, Abraham Mendelssohn, who had married one of Itzig's granddaughters, bought a substantial collection of Bach manuscripts that had come down from C.P.E. Bach, and donated it to the Berlin Sing-Akademie. The Sing-Akademie occasionally performed Bach's works in public concerts, for instance, his first keyboard concerto, with Sara Itzig Levy at the piano.
The first decades of the 19th century saw an increasing number of first publications of Bach's music: Breitkopf started publishing chorale preludes, Hoffmeister harpsichord music, and the Well-Tempered Clavier was printed concurrently by Simrock (Germany), Nägeli (Switzerland) and Hoffmeister (Germany and Austria) in 1801. Vocal music was also published: motets in 1802 and 1803, followed by the E♭ major version of the Magnificat, the Kyrie-Gloria Mass in A major, and the cantata Ein feste Burg ist unser Gott (BWV 80). In 1818, Hans Georg Nägeli called the Mass in B minor the greatest composition ever. Bach's influence was felt in the next generation of early Romantic composers. Abraham's son Felix, aged 13, produced his first Magnificat setting in 1822, and it is clearly inspired by the then-unpublished D major version of Bach's Magnificat.
Felix Mendelssohn's 1829 performance of the St Matthew Passion precipitated the Bach Revival. The St John Passion saw its 19th-century premiere in 1833, and the first public performance of the Mass in B minor followed in 1844. Besides these and other public performances and increased coverage of the composer and his compositions in printed media, the 1830s and 1840s also saw the first publication of more Bach vocal works: six cantatas, the St Matthew Passion, and the Mass in B minor. A series of organ compositions were first published in 1833. Chopin started composing his 24 Preludes, Op. 28, inspired by the Well-Tempered Clavier, in 1835, and Schumann published his Sechs Fugen über den Namen B-A-C-H in 1845. Bach's music was transcribed and arranged to suit contemporary tastes and performance practice by composers such as Carl Friedrich Zelter, Robert Franz, and Franz Liszt, or combined with new music such as the melody line of Charles Gounod's "Ave Maria". Brahms, Bruckner, and Wagner were among the composers who promoted Bach's music or wrote glowingly about it.
In 1850, the Bach-Gesellschaft (Bach Society) was founded to promote Bach's music. In the second half of the 19th century, the Society published a comprehensive edition of his works. In 1854, Bach was deemed one of the three Bs by Peter Cornelius, the others being Beethoven and Berlioz. (Hans von Bülow replaced Berlioz with Brahms.) From 1873 to 1880, Philipp Spitta published Johann Sebastian Bach, the standard work on Bach's life and music. During the 19th century, 200 books were published on Bach. By the end of the century, local Bach societies were established in several cities, and his music had been performed in all major musical centers.
In 19th-century Germany, Bach was coupled with nationalist feeling, and he was inscribed in a religious revival. In England, Bach was coupled with a revival of religious and baroque music. By the end of the century, Bach was firmly established as one of the greatest composers, recognised for both his instrumental and his vocal music.

### 20th century

During the 20th century, the process of recognising the musical as well as the pedagogic value of some of the works continued, as in the promotion of the cello suites by Pablo Casals, the first major performer to record them. Leading performers of classical music such as Willem Mengelberg, Edwin Fischer, Georges Enescu, Herbert von Karajan, Helmut Walcha, Wanda Landowska, I Musici, and Dietrich Fischer-Dieskau recorded his music.
A significant development in the later 20th century was historically informed performance practice, with forerunners such as Nikolaus Harnoncourt acquiring prominence through their performances of Bach's music. Bach's keyboard music was again performed on the harpsichord and other Baroque instruments rather than on modern pianos and 19th-century romantic organs. Ensembles playing and singing Bach's music not only kept to the instruments and the performance style of his day but were also reduced to the size of the groups Bach used for his performances. But that was not the only way Bach's music came to the forefront in the 20th century: his music was heard in versions ranging from Ferruccio Busoni's late romantic piano transcriptions to the orchestrations of Leopold Stokowski, whose interpretation of the Toccata and Fugue in D minor opened Walt Disney's Fantasia, to jazzy interpretations such as those by The Swingle Singers on their album Jazz Sebastian Bach and electronic performances such as Wendy Carlos's Switched-On Bach and The Well-Tempered Synthesizer.
Bach's music has influenced other genres. Jazz musicians have adapted it, with Jacques Loussier, Ian Anderson, Uri Caine, and the Modern Jazz Quartet among those creating jazz versions of his works. Several 20th-century composers referred to Bach or his music, for example Eugène Ysaÿe in Six Sonatas for solo violin, Dmitri Shostakovich in 24 Preludes and Fugues, and Heitor Villa-Lobos in Bachianas Brasileiras. All kinds of publications involved Bach: there were the Bach Jahrbuch publications of the Neue Bachgesellschaft and various other biographies and studies by, among others, Albert Schweitzer, Charles Sanford Terry, Alfred Dürr, Christoph Wolff, Peter Williams, and John Butt, and the 1950 first edition of the Bach-Werke-Verzeichnis. Books such as Gödel, Escher, Bach put the composer's art in a wider perspective. Bach's music was extensively listened to, performed, broadcast, arranged, adapted, and commented upon in the 1990s. Around 2000, the 250th anniversary of Bach's death, three record companies issued box sets of recordings of his complete works.
Three works by Bach are featured on the Voyager Golden Record, a gramophone record containing a broad sample of the images, sounds, languages, and music of Earth, sent into space with the two Voyager probes: the first movement of Brandenburg Concerto No. 2 (conducted by Karl Richter), the "Gavotte en rondeaux" from the Partita for Violin No. 3 (played by Arthur Grumiaux), and the Prelude and Fugue No. 1 in C major from The Well-Tempered Clavier (played by Glenn Gould). 20th-century tributes to Bach include statues erected in his honour and things such as streets and space objects named after him. A multitude of musical ensembles, such as the Bach Aria Group, Deutsche Bachsolisten, Bachchor Stuttgart, and Bach Collegium Japan took the composer's name. Bach festivals were held on several continents, and competitions and prizes such as the International Johann Sebastian Bach Competition and the Royal Academy of Music Bach Prize were named after him. While by the end of the 19th century, Bach had been inscribed in nationalism and religious revival, the late 20th century saw Bach as the subject of a secularised art-as-religion (Kunstreligion).

### 21st century

In the 21st century, Bach's compositions have become available online, for instance at the International Music Score Library Project. High-resolution facsimiles of Bach's autographs became available at the Bach Digital website. 21st-century biographers include Christoph Wolff, Peter Williams, and John Eliot Gardiner.
In 2015, Bach's handwritten personal copy of the Mass in B minor, held by the Berlin State Library, was added to UNESCO's Memory of the World Register, a program intended to protect culturally significant manuscripts.
Alex Ross writes, "Bach became an absolute master of his art by never ceasing to be a student of it. His most exalted sacred works—the two extant Passions, from the seventeen-twenties, and the Mass in B Minor, completed not long before his death in 1750—are feats of synthesis, mobilizing secular devices to spiritual ends. They are rooted in archaic chants, hymns, and chorales. They honor, with consummate skill, the scholastic discipline of canon and fugue. They make expert use of the word-painting techniques of the Renaissance madrigal and Baroque opera. They absorb such stock scenes as the lament, the pastoral, the lullaby, the rage aria, the tempest. They allude to courtly French dances, Italian love songs, [and] the polonaise. Their furious development of brief motifs anticipates Beethoven, who worshipped Bach when he was young. And their most daring harmonic adventures—for example, the otherworldly modulations in the 'Confiteor' of the B-Minor Mass—look ahead to Wagner, even to Schoenberg."
In 2019, Bach was named the greatest composer of all time in a poll of 174 living composers.
The liturgical calendar of the Episcopal Church remembers Bach with a feast day on 28 July; on the same day, the Calendar of Saints of some Lutheran churches, such as the ELCA, remembers Bach, Handel, and Heinrich Schütz.

### Burial site

Bach was originally buried at Old St. John's Cemetery in Leipzig. His grave went unmarked for nearly 150 years, but in 1894 his remains were found and moved to a vault in St. John's Church. This building was destroyed by Allied bombing during World War II, and in 1950, Bach's remains were taken to their present grave in St. Thomas Church. Later research has called into question whether the remains in the grave are actually Bach's.