The reasons which determined Bach to leave Weimar are not quite clear. He was in fact one of those quick-tempered men whom a small irritation might kindle to a resolve of disproportionate gravity. In the present case he had a real grievance in the appointment of a son as successor to the old capellmeister, whose work Bach had done for a long time and the reversion of whose office he might reasonably have counted upon. Leopold, the reigning prince of Anhalt-Coethen was no stranger at Weimar. A family alliance connected the two courts, and it is likely that he had heard Bach there. In any case Bach was known to him by report, and in 1717 was invited to take the post of capellmeister at Coethen.

The six years that Bach spent in the service of this prince make a kind of pause or breathing-space in his life. It is not that he was idle during this period: his work was different. He had, as it were, stepped aside from the road upon which he had journeyed all the years of his manhood, to follow a by-lane where he might loiter if it pleased him. And if this short abandonment of his peculiar art, dedicated to the service of the church, in favour of the writing of suites for strings or clavichord, hardly needs apology, it remains remarkable that Bach consented to take a position in which church music or even organ-playing had no place. In no one of the three churches in Coethen had he any control; perhaps he was not sorry in the present case, since two of them, with the bulk of the population, belonged to (his special aversion) the reformed or Calvinistic sect.22 The Castle Church could boast but an indifferent organ and was unprovided with a choir; so that even had Bach wished to overstep the limitations of his duty, there were no opportunities, but rather discouragement, in Coethen for him to return to his old work.

He was designated Capellmeister and Director of his Highness’s Chamber Music, but in the peculiar situation of the Coethen court the title imperfectly describes the nature of his post. Leopold was a young bachelor who gave to music the loving worship he had not yet consecrated to a woman. He cultivated his art with an eager enthusiasm, sang a full bass, and was no mean performer on violin, viola-da-gamba, and clavichord. He welcomed Bach as a brother in the craft, and not only employed him to compose for his varied requirements, but took him into his familiar fellowship,23 played with him, sang with him, insisted on his company whenever, as was his habit, he journeyed abroad.

Before this he had learned some knowledge of the world, had travelled in England and Italy, and made acquaintance with the music of Rome and Venice. For the future we find him and Bach making repeated visits to Karlsbad and other distant places, and the obedient capellmeister sometimes perhaps a little ennuyÉ, if we may credit a story which relates that on one of these journeys he consoled himself for the lack of all musical instruments by striking off the greater part of the Wohltemperirte Clavier. The incongruous performance recalls the tale of the famous printer, Henry Estiennes, that he divided the New Testament into verses, the verses which we still retain, on a ride from Paris to Lyons.

In spite of the widened experience, it was in truth a narrowing life to Bach. He was not one of a musical group as at Weimar; there is no record of his having any friends in the place. If he had the pleasantness of the grateful appreciation of the Prince, he had no public to sustain his ambition. His days were divided between his house and the music-room of the castle; and he only came into contact with the musical society outside by the custom which he still maintained of employing his holiday in the autumn to visit towns where he was known, where he was invited to try organs and exhibit his skill, or to produce occasional cantatas. Once he went to Leipzig to prove the new organ at the University Church, another time, as has been already mentioned, to Hamburg. Once again he travelled to Halle in the hope of making Handel’s acquaintance, but just missed him.

A visit with Prince Leopold to Karlsbad in 1720, was sadly memorable to Bach. For while he was on his way home and no news could reach him, his wife suddenly fell sick and died. He arrived only to learn that she was already buried. How deep a grief this was to the family—the mother was but thirty-five—we know from the recollection of it which the second son, Philipp Emanuel, then a child of six, bore more than thirty years later. His tender, flexible nature reflected hers closely, as his elder brother Friedemann’s robust vigour did that of his father. And the fact that the two most striking figures, as also the most musical, among Bach’s twenty children sprang from this marriage may be taken in evidence of the near sympathy subsisting between the parents. Else we know nothing of Maria Barbara, and one is apt to depreciate her by comparison with the more gifted woman whom Bach chose for his second wife.

His care was now mainly for the children, four of his seven alone surviving their infancy. The eldest was a daughter, Katharina Dorothea, whom we shall hereafter meet again as helping with her voice in the family concerts; then came three sons, the two already mentioned, and Johann Gottfried Bernhard.24 It was Wilhelm Friedemann, now a lad of ten, who claimed his father’s most anxious attention; and never was a charge fulfilled with greater love and willingness. In later life Bach’s relation to him was one of intimate friendship; already the promise of his musical skill aroused the keenest hopes of his father. He showed afterwards that he had all the characteristics of Sebastian accentuated: stolid independence was carried into wilful obstinacy, hotness of temper into a confirmed irascibility, morose when not violent. At present he was only the hopeful eldest son, for whose sake Bach developed a complete scheme of musical training, beginning with a Clavier-BÜchlein of easy pieces, as early as January, 1720. There is an air of tenderness for the small fingers he loved, and longed to educate, in the ladder of difficulties he so carefully constructed, and in the little preface, in nomine Jesu. This was followed by Inventions in two and three parts, designed to cultivate an equable strength and free motion in all the fingers. The title was apparently chosen to indicate that beyond this he sought to teach in these pieces the elements of musical taste, invention in the scholastic sense being a compound of just disposition of the members and appropriate expression.25 The third stage in the course of instruction was constituted by the preludes and fugues of the Wohltemperirte Clavier, in which technical execution is combined with beauty of form and expression, each in its finest development. One of the points on which Bach insisted was that the practice of the clavichord should from the outset go hand in hand with composition. He assumed that no one should learn to play who could not think musically, as he expressed it; and he never allowed a pupil to compose at the instrument. He would not, he said, have him to be a piano-hussar, a taunt that might well be taken to heart by some of our modern composers. A parallel system of training for the organ was also primarily intended for Friedemann; and both alike shew the clearness and penetration with which Bach understood the functions of a teacher.

In after-years the rector of his school at Leipzig, between whom and Bach there was no love lost, said of him that he was a bad teacher and could not keep order in class. The latter is likely enough, and the former may not be without foundation in the particular case. A man of Bach’s extreme sensibility would certainly appear at his worst in the irritating surroundings of a rude schoolroom. That he could teach, however, and teach better than any man of his time, is proved by the string of distinguished names that appear among his scholars and by the unbroken succession of pupils whom he had in his house from his marriage almost to his death, the applicants increasing in his later days until he was continually forced to turn them back. To his chosen pupils he was kind and genial, and full of encouragement. You have five as good fingers on each hand as I have, was his answer to complaints of difficulty. He never set himself up as a model to which others could not attain: I was obliged, he would say, to be industrious; whoever is equally industrious will succeed as well. From these glimpses of his bearing we may readily conceive the love and enthusiastic reverence which he aroused in his pupils, and as for his irritability, the common failing of great artists, experience shews that at least it does not make a man a bad teacher in private, however much it may militate against his success in a school.

Bach did not remain long a widower. The tradition of his ancestors contained no law requiring a year of mourning; indeed his father married again in seven months. Sebastian was more patient, waited nearly a year and a half, and chose wisely. His new wife, Anna Magdalena Wuelken, held a position as singer at the Coethen court; her father was trumpeter in that of the Duke of Saxe-Weissenfels. She was twenty-one, fifteen years younger than her husband.

The marriage, which took place on the third of December, 1721, was entirely happy. Anna Magdalena proved herself no mere hausfrau, but a real companion to Bach in all his tastes, a helper in work and a sharer in all his pleasures. She had a fine soprano voice, for which her husband delighted to arrange songs and recitatives. Often she copied them out for herself, and besides this her clear well-formed hand, closely resembling Bach’s, occurs constantly in the collections of his manuscripts. On his side he helped her to master the clavichord. Two Clavier-BÜchleins, written for her, exist in his autograph, and to judge by their handsome bindings and the inscriptions in them, were intended as gifts to her, one just after their marriage, in 1722, the other in 1725. She used and added to them afterwards as a sort of album. They contain a great part of what we now know as the French suites, with a variety of preludes, arrangements of airs from his cantatas, &c., and also a set of rules for thorough-bass. It is plain that if the one was an indulgent teacher, the other was a ready and diligent pupil.

The beginning of Bach’s new happiness was soon attended with an unexpected drawback. Prince Leopold married a week after his capellmeister, and from this time forth his interest in music declined. His wife, so unlike Bach’s, cared nothing for music the concerts were still attended, but no longer listened to, and Bach’s work became more and more irksome to him. He had no outside public to take the place of the now indifferent court. He continued, however, for a year, until the death of Kuhnau, the learned and original cantor of the Thomasschule at Leipzig, offered to him an opportunity of returning to that work in the service of the church for which he must have longed all these years. He left Coethen in the summer of 1723, having first composed two church cantatas, as evidence of his fitness for the post. It is probable that, in the hope of the election taking place before Easter, he wrote the S. John Passion Music to grace his arrival, as though to prove that the divorce from sacred music which he had supported for so long a time had made his fertility and creative force only the more abundant. But the delay of the Leipzig authorities postponed the production of this masterpiece. By a coincidence the Princess of Coethen, the determining course of Bach’s removal, died just before he left. Perhaps for the moment he regretted the step he had taken: to us that step is the most fortunate act in his life and the herald of his greatest triumphs.

As we considered the Weimar time as representative of Bach’s career as an organist, so Coethen is the scene of his most extensive production for the clavichord, for the chamber, and for the orchestra. We may therefore here enumerate the compositions that belong to these classes, reserving for the present the great collections of fugues contained in the Wohltemperirte Clavier, of which the second half falls under a later date when the first was alone entirely rearranged and partly rewritten, and the Kunst der Fuge which was the achievement of Bach’s last years.

The clavichord works admit of a double classification. On the one hand we have independent compositions, of which the idea is mostly derived from the organ-style; on the other stand the suites, or sets of pieces in dance-measures, which are moulded upon Italian models. Both alike are adapted by Bach to the clavichord in such a manner that they are completely naturalised in their new-found country. To the former class belong the following works arranged in conformity with Dr. Spitta’s critical results; the numbers refer to Peters’ cheap edition:—

A. Weimar Period.

1. Four Fantasias, in D, A minor, G minor, and B minor (211, p. 28; 215, pp. 3, 30; 216, p. 9):26

2. Four Toccatas, in E minor, D minor, Gr minor and major (210, pp. 3, 30; 211, p. 4; 215, p. 17):

3. Six Fugues, two in A, and two in A minor (212, p. 10; 216, p. 20; 212, p. 14; the fourth in MS. at Berlin), together with two, in A and B minor, on subjects taken from Albinoni (216, p. 25; 214, p. 12):

4. One Prelude and Fugue in A minor (211, p. 14): to these we may perhaps add the well-known one in B flat of which the subject is on the (German) notes contained in the name Bach (B flat, A, C, B natural) but of which the genuineness is suspicious (212, p. 24).

B. Coethen Period.

1. A Fantasia in C minor (212, p. 2).

2. Four Fantasias and Fugues, in D minor (the famous Chromatic Fantasia), B flat, and D (207, p. 20; 212, pp. 28, 32).

3. Two Toccatas, in F sharp minor and C minor (210, pp. 10, 20.)

4. A Prelude in C (printed among the organ works, series v. 8. 3), and two sets of twelve and six little preludes for beginners (200, pp. 3, 14).

5. Five Fugues, in C minor, two in C, and two in D minor (200, pp. 20, 22, 24; 212, pp. 3, 5).

6. Four Preludes and Fugues in D minor, E minor, and two in A minor (200, pp. 26, 28, 33; 207, p. 36).

C. Leipzig Period.

Two Fantasias and Fugues in A minor and C minor (208, p. 22; 207, p. 32 and 212, p. 22, the two parts are separated in the edition).

To this list must be added the two sets of inventions (201) written at Coethen; and the four great Duets (208 p. 36) in which the idea of the invention (or sinfonia) is treated on a much larger scale.27 The duets were written at Leipzig, and it has always been claimed that no skill could possibly add a third real part to them.

In a similar intermediate position stand the two sets of Variations, one in A minor, a Weimar composition, headed alla maniera Italiana (215, p. 10), the other a great series of thirty variations in G, of which notice will be taken in connexion with Bach’s life at Leipzig (209).

The Suites begin at Coethen with the six so-called French Suites (202) and three single sets which probably belong together (214, pp. 18, 26, 32). A solitary suite, in F, bears traces of having been written at Weimar (215, p. 25). At Leipzig Bach produced six Great Suites, known as the English (203, 204), and an equal number of sets of Partitas (205, 206). Another partita of the same period, in B minor, is known from its opening as the French Overture (208, p. 4).28

At Coethen Bach also wrote three sonatas, in A minor, C, and D minor (213, pp. 2, 16, 24), with a fourth which remains only a fragment (212, p. 18).29 These sonatas, the title being to some extent interchangeable with suite, have little in common with the form to which Bach’s son Philipp Emanuel, Haydn, and Mozart (Beethoven can of course not come into the comparison) developed it. The parent of this exists also among Bach’s works, but it has a different name, being distinguished as the Italian Concerto (207, p. 4). It is remarkable that it should bear a designation properly true of an orchestral composition, as though in prevision of the unlimited development of which the form was susceptible.30 But the feeble internal resources of the clavichord, Bach’s chosen instrument for study—the harpsichord was too hard, and the infant pianoforte too coarse for him—prevented him from himself following up the conception. He preferred to write music which was independent of so imperfect an exponent; and his clavichord works are characterised by freedom and delicacy of melody, infinite fancy, and, as we see specially in his fugues, the fullest solidity and richness of structure, rather than by any effects which need a responsive sympathy in the instrument. It is as such that we ought to judge them, however much their life is broadened by performance on the piano.

It is difficult to separate Bach’s chamber compositions from those for orchestra. The orchestras of that day were very small, that at Weimar consisted but of sixteen performers, and Bach’s matured scheme for the production of his church music at Leipzig asked only for a band of twenty. It is wholly uncertain how far it was usual, or considered necessary, to multiply with the parts; in any case chance might often reduce the small orchestra to numbers more consistent with chamber music. That this happened in the concertos which Bach conducted in his own house we may be pretty sure. There is, therefore, little objection to our enumerating both forms of composition in one section.

The Concertos are written on various scales, the use of one instrument concertante being extended to Concerti Grossi requiring as many as four. For the harpsichord there exists six; for two harpsichords two, and for three again two. In another concerto he has combined the harpsichord with two flutes, and in two more with flute and violin, as the three obbligato instruments.

For the violin Bach composed three concertos, besides one apiece for two violins, for violin and hautboy, for two flutes and violin, and for flute, violin, hautboy, and trumpet.

Orchestral works, but for an orchestra of very various constitution, are three of the so-called Brandenburg Concertos,31 and four parties or suites which rank among the most flexible and melodious of all Bach’s creations.32 The list would be increased by nearly thirty works if we added the instrumental symphonies which occur in the course of his cantatas.

As strict chamber music we may reckon his three sonatas or trios, in which the harpsichord combines respectively with two flutes, flute and violin,33 and two violins. For harpsichord and flute there are six sonatas; for harpsichord and violin a like number, together with three separate pieces, a sonata, a partie, and a fugue; finally, three sonatas for harpsichord and viola-da-gamba.

The list of Bach’s instrumental works is completed by two sonatas for obsolete instruments, one for the lute, the other for his own invention, the viola pomposa, and by the memorable sets, of six sonatas each, for the violin and violoncello, which are well enough known in England to render an account of them superfluous.

But a few words are needed in conclusion to mark Bach’s position in reference to the clavichord. In the first place, being acutely sensible of the least falsity of tune, he always tuned the instrument himself, a process which never cost him more than a quarter of an hour. In this art he introduced a great reform, that of tuning on a basis of equal temperament. Without such a reform his chromatic music, and notably his Chromatic Fantasia and the Wohltemperirte Clavier, would have been impossible. Another instance of his fastidious taste is that no one but himself could adjust the quills of a harpsichord to his satisfaction. He took great pains in improving the action of the clavichord, and invented a new instrument, the lute-harpsichord (lauticlavicymbel), with a surprising brilliancy of tone; but the difficulty of tuning it led to its abandonment.

It would demand too technical a discussion if we were to analyse the method of playing which Bach introduced. That he was the first to insist upon an equal use of the thumb with the rest of the hand, and to act upon the principle that touch proceeds from the lower joints of the fingers, and not from the wrist or arm, makes him the founder of the modern art of piano-playing. It is said of him that he “played with so easy and small a motion of the fingers that it was hardly perceptible. Only the first joints of the fingers were in motion; the hand retained, even in the most difficult passages, its rounded form; the fingers rose very little from the keys, hardly more than in a shake, and when one was employed, the others remained still in their position. Still less did the other parts of his body take any share in his play, as happens with many whose hand is not light enough.”34 His playing was light, smooth, swift—powerful or expressive, as he chose—but always without display or the appearance of effort.