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 most characteristic of this style, which Bach did not invent but contributed to so fundamentally that he defined it to a large extent. Fugues are as characteristic to Bach's style as, for instance, the Sonata form is characteristic to 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 of the voices, where the chords formed by the notes sounding at a given point follow the rules of four-part harmony. Forkel, Bach's first biographer, gives this description of this feature of Bach's music, which sets it apart from most other music:
Bach devoted more attention than his contemporaries to the structure of compositions. This can be seen in minor adjustments he made when adapting someone else's composition, such as his earliest version of the "Keiser" St Mark Passion, where he enhances scene transitions, and in the architecture of his own compositions such as his Magnificat and Leipzig Passions. In the last years of his life, Bach revised several of his prior compositions. Often the recasting of such previously composed music in an enhanced structure was the most visible 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 such over-interpretations were later rejected, especially when wandering off into symbolism-ridden hermeneutics.
The librettos, or lyrics, of his vocal compositions played an important 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 he was designing 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.
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.
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.
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 are 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.
According to his obituary, Bach would have composed five year-cycles of sacred cantatas, and additional church cantatas for weddings and funerals, for example. 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.
Bach's cantatas vary greatly in form and instrumentation, including those for solo singers, single choruses, small instrumental groups, and grand orchestras. 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 one with a known date is Christ lag in Todes Banden, BWV 4, for Easter 1707, which is one of his chorale cantatas. Gottes Zeit ist die allerbeste Zeit, BWV 106, also known as Actus Tragicus, is a funeral cantata from the Mühlhausen period. Around 20 church cantatas are extant from his later years in Weimar, for instance, Ich hatte viel Bekümmernis, BWV 21.
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 a period of 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.
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 secular cantatas had 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).
Bach's a cappella music includes motets and chorale harmonisations.
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.
Bach wrote hundreds of four-part harmonisations of Lutheran chorales.
Bach's church music in Latin includes the Magnificat, four Kyrie–Gloria Masses, and the Mass in B minor.
The first version of Bach's Magnificat dates from 1723, but the work is best known in its D major version of 1733.
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.
Bach wrote for organ and for stringed keyboard instruments such as harpsichord, clavichord and lute-harpsichord.
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 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 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. Bach was extensively engaged later in his life in consulting on organ projects, testing new organs and dedicating organs in 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.
Bach wrote many works for harpsichord, some of which may also have been played on the clavichord or lute-harpsichord. Some of his larger 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.
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 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 instruments or combinations of instruments.
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".
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.
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, now lost. A number of violin, oboe, and flute concertos have been reconstructed from these.
In addition to concertos, Bach wrote four orchestral suites, each suite being a series of stylised dances for orchestra, preceded by a French overture.
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, and 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.
Throughout the 18th century, the appreciation of Bach's music was mostly limited to distinguished connoisseurs. The 19th century started with publication of the first biography of the composer and ended with the completion of the publication of all of Bach's known works by the Bach Gesellschaft. A Bach Revival had started from Mendelssohn's performance of the St Matthew Passion in 1829. Soon after that performance, Bach started to become regarded as one of the greatest composers of all times, if not the greatest, a reputation he has retained ever since. A new extensive Bach biography was published in the second half of the 19th century.
In the 20th century, Bach's music was widely performed and recorded, while the Neue Bachgesellschaft, among others, published research on the composer. Modern adaptations of Bach's music contributed greatly to his popularisation in the second half of the 20th century. Among these were the Swingle Singers' versions of Bach pieces (for instance, the Air from Orchestral Suite No. 3, or the Wachet auf... chorale prelude) and Wendy Carlos' 1968 Switched-On Bach, which used the Moog electronic synthesiser.
By the end of the 20th century, more classical performers were gradually moving away from the performance style and instrumentation that were established in the romantic era: they started to perform Bach's music on period instruments of the baroque era, studied and practised playing techniques and tempi as established in his time, and reduced the size of instrumental ensembles and choirs to what he would have employed. The BACH motif, used by the composer in his own compositions, was used in dozens of tributes to the composer from the 19th century to the 21st. In the 21st century, the complete extant output of the composer became available on-line, with several websites exclusively dedicated to him.
In his own time, Bach was highly regarded amongst his colleagues, although his reputation outside of this small circle of connaisseurs was due not to his compositions (which had an extremely narrow circulation), but due 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. Such highly placed appreciation contrasted with the humiliations he had to cope with, for instance in Leipzig. Also in the contemporary press, Bach had his detractors, such as Johann Adolf Scheibe, suggesting he write less complex music, and his supporters, such as Johann Mattheson and Lorenz Christoph Mizler.
After his death, Bach's reputation as a composer at first declined: his work was regarded as old-fashioned compared to the emerging galant style. Initially, he was remembered more as a virtuoso player of the organ and as a teacher. The bulk of the music that had been printed during the composer's lifetime, at least the part that was remembered, was for the organ and the harpsichord. Thus, his reputation as a composer was initially mostly limited to his keyboard music, and that even fairly limited to its value in music education.
Bach's surviving family members, who inherited a large part 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 the bulk of previously unpublished works of his father were preserved with his help. 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 works by Johann Sebastian Bach and his sons and was a "patron" of CPE Bach.
While in Leipzig, performances of Bach's church music were limited to some of his motets, and under cantor Doles some of his Passions. A new generation of Bach aficionados emerged: they 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 such connoisseur 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).
In 1802, Johann Nikolaus Forkel published Ueber Johann Sebastian Bachs Leben, Kunst und Kunstwerke, the first biography of the composer, which contributed to his becoming known to a wider public. 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. When Felix Mendelssohn, Abraham's son, aged 13, produced his first Magnificat setting in 1822, it is clear that he had been inspired by the then unpublished D major version of Bach's Magnificat.
Felix Mendelssohn significantly contributed to the renewed interest in Bach's work with his 1829 Berlin performance of the St Matthew Passion, which was instrumental in setting off what has been called the Bach Revival. The St John Passion saw its 19th-century premiere in 1833, and the first performance of the Mass in B minor followed in 1844. Besides these and other public performances and an increased coverage on the composer and his compositions in printed media, the 1830s and 1840s also saw the first publication of more vocal works by Bach: six cantatas, the St Matthew Passion, and the Mass in B minor. A series of organ compositions saw their first publication 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 the composer's works. Also in the second half of the 19th century, Philipp Spitta published Johann Sebastian Bach, the standard work on Bach's life and music. By that time, Bach was known as the first of the three Bs in music. Throughout 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 centres.
In Germany all throughout the century, Bach was coupled to nationalist feelings, and the composer was inscribed in a religious revival. In England, Bach was coupled to an existing 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.
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 these suites. Leading performers of classical music such as Willem Mengelberg, Edwin Fischer, Georges Enescu, Leopold Stokowski, Herbert von Karajan, Arthur Grumiaux, Helmut Walcha, Wanda Landowska, Karl Richter, I Musici, Dietrich Fischer-Dieskau, and Glenn Gould recorded his music.
A significant development in the later part of the 20th century was the momentum gained by the historically informed performance practice, with forerunners such as Nikolaus Harnoncourt acquiring prominence by their performances of Bach's music. His keyboard music was again performed more on the instruments Bach was familiar with, 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 far from 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 jazzy interpretations such as those by The Swingle Singers, orchestrations like the one opening Walt Disney's Fantasia movie, and synthesiser performances such as Wendy Carlos' Switched-On Bach recordings.
Bach's music has influenced other genres. For instance, jazz musicians have adopted Bach's music, 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: not only were there the Bach Jahrbuch publications of the Neue Bachgesellschaft, various other biographies and studies by among others Albert Schweitzer, Charles Sanford Terry, Alfred Dürr, Christoph Wolff. Peter Williams, John Butt, and the 1950 first edition of the Bach-Werke-Verzeichnis; but also 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 with complete recordings of Bach's music.
Bach's music features three times—more than that of any other composer—on the Voyager Golden Record, a gramophone record containing a broad sample of the images, common sounds, languages, and music of Earth, sent into outer space with the two Voyager probes. Tributes to Bach in the 20th century include statues erected in his honour and a variety of things such as streets and space objects being named after him. Also, a multitude of musical ensembles such as the Bach Aria Group, Deutsche Bachsolisten, Bachchor Stuttgart, and Bach Collegium Japan adopted 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 the composer. 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).
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 2019, Bach was named the greatest composer of all time in a poll conducted among 174 living composers.
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 located and moved to a vault in St. John's Church. This building was destroyed by Allied bombing during World War II, so 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 those of Bach.
The liturgical calendar of the Episcopal Church remembers Bach annually with a feast day on 28 July, together with George Frideric Handel and Henry Purcell; on the same day, the Calendar of Saints of the Lutheran Church remembers Bach and Handel with Heinrich Schütz.