First section

Feeding the hungry, detail from Caritas, The Seven Acts of Mercy, Pieter Bruegel the Elder, 1559

The movement opens with an extensive orchestral sinfonia marked Concerto in the autograph score. Lasting 22 bars, this ritornello establishes the prevailing anguished mood of the first section. It is heard twice again, but only as the accompanying backdrop for the separate musical material of the chorus, a setting of the first phrase of the Old Testament text. The open motifs are also heard again in the fragmentary accompaniment of the central choral fugato episode between the two reprises of the ritornello. The different motifs in the ritornello thus also serve the purpose of accompanying specific parts of the text. The first predominant motif consist of detached repeated quaver chords, passed antiphonally between the three instrumental groups of recorders, oboes and strings. These are accompanied by similarly detached crotchets, scored as quavers with rests, in the walking bass of the continuo. After thirteen bars there follows a four bar passage of melifluous semiquaver passages in thirds for the recorders with imitative responses from the oboes; the upper strings take up the detached crotchets and the continuo the groups of detached repeated quavers. In the four succeeding bars the quaver figure in the continuo line is replaced by a new motif of rising semiquaver scales, with the detached quavers and crotchets passing into the upper strings and the woodwind playing sustained chords. In the concluding two bars of the sinfonia the semiquaver scale motif passes into the recorders in thirds and is taken up by the other instruments for the sustained final cadence.^[4][27][25]

Several commentators, most notably Spitta (1899) and more recently Dürr & Jones (2006), have interpreted the repeated quaver figures passed between different groups of instruments as "unmistakably depict[ing] the gesture of breaking bread."^[28] Spitta also felt that the detached notes, which subsequently accompany quite different text, added "a tender, dreamy tinge" to the movement. For Schweitzer (1911) and subsequent commentators like Robertson (1972), however, the motif represented the "uncertain, tottering steps ... of the wretched ones who are being supported and led into the house."

After the closing cadence of the sinfonia, there is a reprise of the ritornello in the orchestra in a slightly expanded form. Immediately the chorus enters in pairs with their own musical material, singing in homphonic form. The word "brich" (break) in their initial declamatory phrase "Brich dem hungrigen dein Brot" is echoed in the pauses in the musical setting, pauses already present in the fragmentary detached quavers of the accompaniment. Equally well the repetition of this phrase is broken for one bar during which the original texture of the sinfonia is briefly heard again. Gardiner (2004) describes the musical material as representing "imploring gestures, emotionally choked, their pleas breaking and stuttering." In contrast the following phrase "und die, so in Elend sind" has sustained melismas in all the parts on the word "Elend" (misery), with chromaticism, suspensions and descending quaver figures.

There is a further contrast in the next phrase "führe ins Haus" where the soprano and alto are paired with a long lyrical melisma in semiquavers on the word "führe" (lead). This new musical material is matched by the semiquaver figures of the woodwind. Similarly the detached quaver accompaniment in the continuo is matched by parallel figures in the tenor and bass parts. In the next four bars of this second rendition of the sinfonia, there is a reprise of the rising semiquaver figures in the continuo and sustained chords in the woodwind. In the first two bars each voice in the chorus enters successively with a new rising fourth motif for the phrase "und die" before the music intensifies as the chorus joins the sustained chords of the woodwind for the word "Elend". The final two bars of the closing cadence of the ritornello are more complex. On the one hand the mounting tension in the previous bars is resolved with the phrase "führe ins Haus" in the soprano, alto and bass voices.

On the other hand, in the first of these two bars the tenor part embarks on the fugal subject of the following fugato section. The beginning of the subject is thus partially hidden or overlaid by the two bar cadence, from which it emerges. The condensed subject of the fugue incorporates the rising fourth motif for "und die" as well as the motif of rising semiquaver scales from the ritornello and the descending semiquaver scale from the soprano-alto melisma on "führe".

In the fugato section each voice in the chorus sings the fugal subject following the tenors: the altos come in next, emerging from the tenor part; then the sopranos, emerging from the alto part; and finally the fourth statement of the subject in the basses leads into a true repetition of the closing two bar cadence of the ritornello, with a reprise of the original accompaniment in the orchestra, thus concluding the fugato episode. As Gardiner (2004) comments, the first tenor entry with its prominent A flats and D flats "has a pathos all of its own, especially when for eight bars it is joined in imitation by the altos." The musicologist André Pirro notes that the A flat–D flat motif in the fugal subject on the word Elend is typical of Bach's use of suspended figures to evoke the burden of suffering and misery.

After the fugato episode, the ritornello resumes for a third time, with the chorus singing a variant of their homophonic material with much of the counterpoint inverted; this time, however, there is no fugal episode inserted before the final two bar cadence.^{[4][27][25][28][29][30][31]}

Intermediate section

Clothing the naked, detail from Caritas, The Seven Acts of Mercy, Pieter Bruegel the Elder, 1559

The short second section in common time is a 12 bar bridging interlude linking the first and third sections. The key modulates from D minor to C minor, so that the surrounding first and third sections can modulate from their starting key to its dominant and thus the whole movement can return to its original key at the close.^[32][33]

The bridging section is composed in the seventeenth century concertato style, adopted in many of Bach's earlier Weimar cantatas, with the chorus playing the role of the concertino soloists and the orchestra the ripieno. The movement starts off with the basses singing "so du einen nacket siehest" (when thou naked seest), without any accompaniment even from the continuo.

The full choir and orchestra respond with "so kleide ihn" (then clothe him), with alto recorders echoing the initial bass theme. In the next concertino passage the bass theme is sung by the altos, while the sopranos sing a florid counter-theme with semiquaver scales—a long melisma on "kleide".

The bass theme is finally sung by the tenors, with the florid accompaniment in the altos and sopranos. In the second set of six bars, the choir sing the text "und entzeuch dich nicht von deinem Fleisch" (and hide not thyself from thine own flesh) in chords, taking up the repeated detached notes of the initial bass theme. The bass line incorporates the semiquaver scales.

The beginning of the bass part provides a motif for the continuo accompaniment, which is imitated in counterpoint by the two alto recorders until the end of the section, producing a running line of semiquavers. The accompanying oboes and upper strings respond to each other with fragmented quaver motifs derived from the vocal material of this section as well as the quaver motifs in the first section.

Pirro (2014) has pointed out that the musical device of silencing parts of an ensemble is frequently used by Bach as a form of musical iconography. In this case the unaccompanied basses are "the musical equivalent of nakedness", while in contrast the full orchestra and chorus "unfolds itself in broad drapings to urge the merciful charity signified by the words 'clothe him'." This section is more lively than the first with a greater feeling of urgency.^{[32][33][4][29][34]}

Final section

The prophet Isaiah, woodcut by Hans Holbein the Younger, 1538

In the last section in spirited 3/8 time, the predominant mood is of joyous exaltation reflecting the text from Isaiah. The structure of the choral material in this final section complements that of the first section; there a fugal passage was enclosed between two homophonic episodes; here a homophonic episode is preceded and followed by fugal passages. While the first section is preceded by the lengthy orchestral sinfonia, the final section ends with a short coda for full chorus and orchestra.

The fugue subject starts to the words "Alsdann wird dein Licht herfürbrechen wie die Morgenröte" in the tenor voice with an upbeat, continuing for seven bars as it begins a long melisma on the first syllable of "röte" (dawneth).^[35] In the seventh bar the alto voice enters with the same subject, at which point the tenors takes up the material of the counter-subject for the next seven bars to conclude the melisma. Beneath both parts the continuo plays its own independent material, built up from two motifs: the first motif is a sospirans figure made up of four semiquavers followed by a scale of four ascending quavers, heard in the first two bars; and the second, which starts in the fifth bar, is an angular three-note quaver motif that descends in a sequence.

The altos and tenors are joined after seven bars by the fugue subject in the soprano voice. After a further seven bars the basses sing the last statement of the subject, accompanied by the full orchestra playing colla parte except for the two alto recorders, bringing the first fugato section to a close. The alto recorders play fragmented quaver figures in unison some of which are derived from the angular three-note continuo motif, leading into the first seven bar homophonic choral passage.

With a colla parte accompaniment in the oboes and continuo, the chorus sing the text "und deine Besserung wird schnell Wachsen" in clipped motet-style with chords and dotted rhythms, until a florid melisma in semiquavers on "Wachsen" (prosper). They are accompanied in the upper strings by detached quavers on the second and third beats of each bar; while the two alto recorders play in unison their own florid line of running semiquavers derived from the semiquaver figures in the fugue counter-subject.

This homophonic choral passage is followed by the first of three short four-bar orchestral ritornellos, with a texture that has already been heard very briefly in the bar when the chorus pause between the fugato and homophonic passages. As in the opening sinfonia, the instruments play in four distinct groups—alto recorders, oboes, upper strings and continuo—but the sparseness there is now replaced by a jubilant canzona-style flourish.

The semiquaver motifs in the alto recorders were already heard in the second and third bars of the obbligato accompaniment to the homophonic episode, but here they play in thirds. The other orchestral groups play pairs of detached quaver chords, with upper strings on the beat and oboes off the beat. The choir then rejoin the orchestra for the second of the three homophonic passages to the text "und dein Gerichtigkeit wird vor dir hergehen". At fourteen bars in length, it is the longest and most complex of the three. The broad structure of the episode is a canon between the soprano and bass parts.

The canonic entries are separated by a bar until the stretto starting in the ninth bar when they are separated by a quaver. The vocal line is ingeniously composed from figures that have already been heard in the section: the start of the fugue subject; the initial sospirans continuo motif with its second part inverted and in dotted rhythm, like the opening "hungrigen" of the first section; the semiquaver scales in the fugue subject and their inversions; and the portion of the fugue counter-subject with suspensions. There are two melismas on "hergehen" (go onward), with the second one—during the stretto—rising to a climax before a concluding two bar cadence similar to the one in the first homophonic passage. The alto and tenor voices at first accompany the canon with imitative figures; but during the stretto the alto pairs with the soprano in thirds and the tenor pairs with the bass. The rest of the orchestra play colla parte with the singers except for the alto recorders. As in the first homophonic section they play an obbligato accompaniment in unison. Before the stretto it is formed of running semiquavers, made up of the ritornello motif and the scales of the vocal parts. During the stretto they play anapaests—motifs of joy—off the beat, increasing the level of excitement and adulation. in all the voices After the cadence, the movement is punctuated by a second rendition of the four-bar orchestral ritornello. This time the oboes play the semiquaver motif, the alto recorders play the pair of detached quavers on the beat and the upper strings those off the beat. This leads into the second fugato episode in the key of C minor.

The fugue subject, initially sung by the basses to the words "und die Herrlichkeit des Herrn wird dich zu sich nehmen", is a slight variant of the original one. This can be seen by comparing the tenor line in the first fugato episode with the alto entry in the second.

Pieter Bruegel the Elder, Sermon of St John the Baptist, 1566: the multitude gather to hear John the Baptist as he tells them that the kingdom of heaven is at hand and enjoins them to acts of charity.^[36]

Like the first and second homophonic passages, however, the first and second fugato episodes differ in unexpected ways, resulting in a more elevated mood and richer orchestral texture. The fugato episode is lengthened by having a new fifth fugal voice provided by the alto recorders in unison, scored in flowing semiquavers. The chorus and alto recorders enter in the following order: basses, tenors, altos, alto recorders and finally sopranos. All the voices have long melismas on the word "nehmen" (reward). The continuo reprise the accompaniment of the first fugato episode during the first statement of the fugue subject and counter-subject in the basses. This time, however, there is an additional accompaniment from the two alto recorders consisting mainly of the quaver motifs from the ritornello. The alto recorders then briefly fall silent, while the basses unite with the continuo part, singing its independent musical material until the end of the episode. After the first entry of the basses, the other instrumental groups enter to play colla parte with each new voice: the violas enter with the tenors; the second oboe and second violins enter with the altos; the two alto flutes enter in unison; and finally the sopranos enter with the first oboe and first violins. The anticipated entry of the sopranos after the altos is further delayed by the extension of the fugue subject in the alto recorders by four bars, with repetitions of the figures in bars 1–2 and 5-6; all the material is played at unexpected pitches. Below the fugue subject in the two recorders, the altos and tenors sing imitative syncopated responses based on the counter-subject, leading up to the true entry of the sopranos. With the recorders taking up the counter-subject, the sopranos sing the fugue subject at its expected pitch, with the imitative polyphony continuing in the middle voices, bringing the fugato episode to its concluding cadence.

The orchestral ritornello punctuates the movement for a third and last time, the upper strings playing the semiquaver figures, with the detached quavers on the beat in the oboes and off the beat in the alto recorders. It leads directly into the homophonic coda in the last seven bars of the movement. With the same orchestral pairings as the fugato episode, the sopranos joyously sing out the beginning of the second fugue theme below trilling recorders before joining the polyphony of the other voices—with a last emphatic sospirans figure in the basses—for the final exultant rendition of the text.^[37]

As Whittaker (1959) states, this "short tutti outburst ... closes this superb chorus in a blaze of 'Herrlichkeit'." Gardiner (2004), commenting on the change of mood in the final section, writes, "The sense of relief after the stifling pathos of the opening sections is palpable ... After so much pathos, the final coda led by the sopranos releases the pent-up energy in an explosion of joy." Robertson (1972) comments, "The words, to the end of this section, are based on Isaiah 58:7-8 ... It brings Jesus' words to mind, 'Inasmuch as you do it unto them, you do it unto me' and his denunciation of the careless rich. Isaiah continues, 'Then shall thy light break forth as the morning and thy healing shall spring forth speedily; and thy righteousness shall go before thee.' Bach sets the paraphrase of these last words to a glorious fugue, with two expositions, and so brings to an end one of his finest choruses and one that is worthy indeed of the inspired words of Isaiah." Spitta (1899) also expresses his admiration for Bach's setting: "The chorus of the first movement, set to two beautiful verses of Isaiah, brings out the meaning of that text in the Sermon on the Mount, 'Blessed are the merciful, for they shall obtain mercy', and the cantata is fitly concluded with the sixth verse of the paraphrase of the beatitudes. It is an affecting picture of Christian love, softening with tender hand and pitying sympathy the sorrow of the brethren, and obtaining the highest reward." Cantagrel (2010) describes the perfect balance in the proportions of the different sections, "marking a magnificent journey from darkness into light": the first fugato episode represents "the light emanating from the merciful walking in the paths of righteousness"; the second "the light of the glory of God".