Like the music of the preceding centuries, the music of J.S. Bach is primarily contrapuntal, but with a huge difference. In sticking to contrapuntal textures, J.S. Bach was considered more a reactionary than a revolutionary, but he solidified two of the revolutionary changes that culminated in his time.

First, the free-floating rhythms of plainsong, that continued to flow in the polyphonic motets of the Renaissance period, were structured into a metric system where the music followed a definite beat in a definite tempo. This development led to the motoric effect of baroque music where the basso continuo provided a constant beat over which the melodic lines had the freedom to move as they wished. Although the metered rhythm tended to give music a mechanical quality, especially in the hands of the mediocre, its underlying structure could support great complexities in rhythmic organization. Syncopation takes on significant meaning when it is set off against a steady beat. Hence the affinity of Bach's music with jazz.

Another complexity allowed for by metric rhythm was the enrichment of counterpoint, allowing for double, triple, even quadruple fugues. Although earlier music was capable of expressing contrasting musical ideas simultaneously, imitation normally used one subject at a time, subject to transformation as it was, to set off the musical flow. The steady beat introduced into baroque music made it much easier to introduce two contrasting themes and treat both of them contrapuntally at the same time. The Gratia Agimus Tibi chorus from the B Minor Mass gains its power through the development of two stately fugue subjects that, together, build up to a climax. The "St. Anne" Fugue in E-flat is a triple fugue where Bach exploits the opportunity to portray Trinitarian theology in music through the intertwining of three rhythmically contrasting themes, clearly distinct, yet unified through their intimate relationships with one another.

The rhythmic stability in baroque music makes Bach square, compared to the exuberantly unregulated rhythmic flow of Renaissance music. By square, I do not mean stodgy; I mean that the music is solid, anchored to the ground. Within this four-square anchoring, the musical lines soar up to Heaven and beyond. Steady rhythm, of course, had already developed in Renaissance dance music. These dance rhythms were considered too worldly for sacred music and were shunned by the Church during that era. The solidification of meter brought all music in touch with the motions of dance, whose steps must be made on the ground, however high the dancer might leap. The dance rhythms of Bach's concertos and suites are imported into his sacred music. God is welcomed into our world where God can dance with us.

Second, the tonal system that had been emerging from the modal system for some time was finally put firmly in place. Bach had a more active hand in this development through his publication of The Well-Tempered Clavier. The compromise of equal temperament, which put all the notes slightly out of tune with each other, but to a minuscule degree not easily detected by the ear, freed up all twelves notes of the chromatic scale so that all could be used in the same piece, even in the same passage of music. The Well-Tempered Clavier demonstrates how equal-temperament allows the harpsichord to play all twenty-four keys. The availability of the twelve notes also allowed for chromaticism, which Bach also amply exploited. The Chromatic Fantasy and Fugue in D Minor is a particularly dramatic example. The fugue subject of the B Minor Fugue at the conclusion of Book I of The Well-Tempered Clavier includes all twelve notes, which bring it perilously close to Arnold Schoenberg's territory. (I think we have to wait until Franz Liszt before we come across another theme with all twelve notes in it.)

While dance-rhythms did their share in grounding music on the earth, the tonal system brought the emotional range into the day-to-day working of the human heart. It is now earthly joys and sorrows that are expressed even in sacred music. However, just as a dancer can leap high from the earth, so does the sorrow of earthly loss, expressed so movingly in the slow movements of Bach's violin sonatas, yearn for life beyond human reasoning. Moreover, European religious thought had shifted to a much greater stress on the human drama of salvation than in earlier centuries. In Bach's Lutheran tradition, the drama focused on human helplessness, even despair, over sin, and the intervention of God's saving grace. The tonal musical language was eminently suited for portraying this drama. Cantata no, 105, Herr, Gehe nicht ins Gericht, (Lord, enter not into Judgement) is one among many powerful examples in the cantatas. The opening chorus is divided into two contrasting parts. The first, in G Minor, has the chorus pleading to God for mercy. Dramatic entries on the word "Herr" are followed by climbing lines on the rest of the phrase. The drama is heightened by the chromatic capabilities that allow wandering into a key as distant from G Minor as B Minor. The second part is a lively fugue that doesn't exactly dispel the anxiety of the first part, but comes across as much more confident in God's mercy, although there is no righteousness among the living. The contrast is strong enough that the ear is easily fooled into thinking that the key has shifted to the relative major, even though it remains in G Minor. The two arias get at the heart of the drama. The Soprano aria Wie zittern und wanken der Sünder Gedanken programmatically expresses humanity's fear before God's judgment with rapidly repeated chords that portray the quaking heart. The bass line is left out so that the shaking chords are done in the relatively high register of the violins and violas, thus accentuating the Lutheran notion that humanity has no ground, of itself, to stand on before God. Over this accompaniment, a searing melody played by the oboe and sung by the soprano in counterpoint expresses the human anguish. The brief accompanied recitative for bass is the dramatic turning point as the soloist proclaims the redemption brought by Christ through his blood. In the following aria, the tenor and horn soloist celebrate the God's deliverance with a confident melody grounded solidly in B-flat, accompanied by joyful, rapid figures in the first violins. The final chorale recaps this drama in miniature as the quaking figure from the soprano aria returns to accompany the choir. However, after each line of the chorale, the rhythm of the quaking slows down until, at the end, the orchestra settles on a serene cadence on G Major.

The expression of human religious pathos reaches one of its highest points in the St. Matthew Passion. However, although the suffering portrayed in this work is recognizably human, the grandeur and slow pace of the work make it transparent to the heart of God. The combination of double fugue and dialogue between the two choirs, topped by a cantus firmus chorale sung by a treble choir, makes it clear that this is a tragedy of ultimate proportions. The alto arias Buss und Reu and Erbarme Dich, depicting the woman who anointed Jesus and Peter after his denial respectively, make remorse as dignified as it is deep. Bass arias that express the believer's desire to share in drinking Jesus' cup at Gethsemane and then carrying the cross for Jesus portray both the pain and the love that make up those sentiments. When Jesus is led away from Gethsemane, the whole world cries out in protest to the tune of a furious fugue where the lightning flashes in the fugue subject and the thunder rolls in the bass runs of the countersubject. At the end, Jesus is laid in the tomb to the bittersweet lullabies of the fervent aria Mache Dich mein Herze Rein and the final chorus that brings back the dramatic dialogue with which the work began.

Perhaps the two most comprehensive works are that masterpieces: The Goldberg Variations and the monumental B Minor Mass. The combination of intricate counterpoint, the range of moods that includes a tavern song woven into the theme at the end, and the strict order that, magically, room for all manner of dance, makes The Goldberg Variations one of the most comforting works I know through its ability to order the world. The B Minor Mass is surely Bach's fullest musical and religious testament. By including those portions of the mass no longer included in the Lutheran service, this work stands as an ecumenical gesture to the whole of Christendom. The Kyrie and Gloria combine to give us, one last time, the drama of the human plea for mercy answered by the proclamation of God's glory. The Credo encompasses the drama of salvation. The work closes with the stately dance of the Sanctus and the Agnus Dei, which, contrasts the pathos of Christ's suffering as the Lamb of God with a repeat of the Gratia Agimus Gloria tibi chorus to the words: Dona nobis pacem. As often pointed out: Bach did not need to ask for God's peace, he could thank God for it.