supreme arbiter and lawgiver of music, a master comparable in greatness of stature with Aristotle in philosophy and Leonardo da Vinci in art; b. Eisenach, Mar. 21 (baptized Mar. 23), 1685; d. Leipzig, July 28, 1750. Bach was born to an illustrious family of musicians who were active in various capacities as performing artists, composers, and teachers. He attended the Latin school in Eisenach and apparently was a good student. His mother died in 1694; his father remarried but died soon afterward. Bach was then adopted by his brother Johann Christoph (1671-1721), who supported his musical studies. In 1695 he began attending the Lyceum, Ohrdruf, and five years later, was admitted to the Mettenchor (choir) of the Michaeliskirche (St. Michael's Church), Lüneburg (1700).

Bach's first professional position came in 1703 when he was hired as the organist at the Neukirche (New Church) in Arnstadt. In 1705 he obtained a leave of absence to travel to Lübeck to hear the famous organist DIETRICH BUXTEHUDE (cl637-1707). Buxtehude was famous for his highly ornamented style of playing the organ, and Bach would be inspired by hearing him play to add more ornamentation to his work.

In 1707 Bach became organist at the Blasiuskirche in Mühlhausen and also married his cousin Maria Barbara (1684-1720). In 1708 Bach presented his first published work, his cantata Gott ist mein König (God is my King; BWV 71), for the installation of a new Mühlhausen town council. Although his employment in Mühlhausen was satisfactory, he resigned that summer after receiving the better-paid post of court organist to Duke Wilhelm Ernst of Weimar. In 1714 the duke gave Bach the position of Konzertmeister (concert master), at a time when Bach considered taking a position in Halle. Three years later Bach accepted the position of Kapellmeister and music director to Prince Leopold of Anhalt in Cöthen (1717), but his request for release was at first refused by Wilhelm Ernst, who imprisoned Bach for a month in late 1717 before allowing him to leave.

The Cöthen period was one of the most productive and least troubled in Bach's life. During this time he composed much of his great instrumental music: the set of six BRANDENBURG concertos, Clavierbüchlein [Clavier Book] für Wilhelm Friedemann Bach, book 1 of Das Wohltemperierte Clavier (THE WELL-TEMPERED CLAVIER), and the solo violin and cello works. In 1720 Bach accompanied Prince Leopold to Karlsbad; while he was away, his wife Maria Barbara took ill and died, leaving Bach to care for their seven children. He remained a widower for nearly a year and a half before he married Anna Magdalena Wilcken (1701-60), the daughter of a Weissenfels court trumpeter. They had thirteen children during their happy marital life.

In 1721 Bach completed his Brandenburg Concertos. It was also in the early 1720s that Prince Leopold married a woman who had no interest in music; Bach was thus ready to consider a job change. When Johann Kuhnau, the cantor of Leipzig, died in 1722, Bach applied for the post and was officially hired in 1723. As director of church music, Bach supervised musicians in four churches, provided music for performance at two of them, and taught at the Thomasschule, a school for training young choirboys. There were more mundane obligations that Bach was expected to discharge (for example, gathering firewood for the Thomasschule), about which Bach had many disputes with the rector. In Leipzig Bach created his greatest sacred works: the ST. MATTHEW PASSION (BWV 244), St. John Passion (BWV 245), the B Minor Mass (BWV 232), Magnificat (BWV 243), the holiday oratorios, and most of the church cantatas. In 1729 he organized the famous Collegium Musicum, made up of professional musicians and university students with whom he gave regular weekly concerts, leading this group until 1737 and again from 1739 to 1741. He made several visits to Dresden, where his son Wilhelm Friedemann was organist at the Sophienkirche.

In the late 1740s Bach's health began to fail. He suffered from a cataract that was gradually darkening his vision. An operation in 1749, performed with the crude tools of the time, left him almost totally blind. It is said that his vision suddenly returned in mid-1750, but he then suffered a cerebral hemorrhage, and a few days later he was dead. Bach's final work, Die Kunst der Fuge (The Art of Fugue), designed to show the range and depth of counterpoint, remained unfinished.

Bach made many contributions to music history. His collection The Well-Tempered Clavier (in 2 books, 1722, 1742), often referred to as "the 48," contains 48 preludes and 48 fugues in all major and minor keys arranged in chromatic order, alternating in major and minor keys. It showed the importance of tuning keyboard instruments in EQUAL TEMPERAMENT, then a new concept, in order to play in a wide range of keys without producing unpleasant or out-of-tune notes.

Bach was one of the great masters of VARIATION, or creating different versions of the same melody. A superb example is his set known as the GOLDBERG VARIATIONS (BWV 988), so named because it was commissioned by the Russian diplomat Keyserling through Bach's pupil J. G. Goldberg (1727-56) , who was in Keyserlings service as a harpsichordist.

A different type of Bach's great musical compositions is his Concerts à plusieurs instruments, better known as the Brandenburg Concertos (BWV 1046-51) because of their dedication to Christian Ludwig, margrave of Brandenburg (possibly because Bach was seeking to win a position from him). They represent the crowning achievement of BAROQUE orchestral music; Nos. 2, 4, and 5 are examples of CONCERTO GROSSO, in which a group of solo instruments (CONCERTINO) is contrasted with the accompanying string orchestra (RIPIENO).

Die Kunst der Fuge (The Art of Fugue; BWV 1080), Bach's last composition (begun in 1749), is an encyclopedia of fugues, CANONS, and COUNTERPOINT based on the same theme, using various methods of composition including INVERSION, canon, AUGMENTATION, DIMINUTION, DOUBLE FUGUE, and TRIPLE FUGUE.

Of Bach's 20 children, 10 reached maturity. His sons WILHELM FRIEDEMANN, CARL PHILIPP EMANUEL, Johann Christoph Friedrich, and JOHANN (JOHN) CHRISTIAN made their mark as independent composers. Contrary to conventional wisdom, Bach was not unappreciated by his contemporaries. His sons kept his legacy alive for a generation after Bach's death, however much their own styles might have differed. WOLFGANG AMADEUS MOZART, LUDWIG VAN BEETHOVEN, and FRÉDÉRIC CHOPIN studied Bach's preludes and fugues. While FELIX MENDELSSOHN'S Berlin revival of the St. Matthew Passion (1829) was an important event, Bach's works were never really forgotten. They remain a core part of the classical repertory to today.

The standard Bach thematic catalogue is W. Schmieders Thematisch-systematisches Verzeichnis der musikalischen Werke von J. S. B. (Bach-Werke-Verzeichnis or BWV) (Leipzig, 1950; 3d ed., 1961).