Johann Sebastian Bach was a Lutheran by profession, a Lutheran by personal persuasion, and a Lutheran in his musical practice. Before he took up his post as cantor in Leipzig, he went through two theological examinations, which he passed by endorsing the Formula of Concord, a statement of faith from 1577 that encapsulated the high points of Martin Luther's theology. The inventory of Bach's books made after his death included two sets of Luther's works (one in German, one in Latin) and several volumes of his miscellaneous writings, along with a number of major works by Lutheran theologians.

Bach stood squarely in the Lutheran tradition, not just in following the substance of Luther's theology, but also in actively building upon what Luther had accomplished as a writer of hymns and a promoter of church music. What Bach harvested was a seed planted by Luther himself.

The dawn of the theological Reformation in Germany was also the dawn of Protestant church music, and the principal agent for both was Martin Luther. Luther's importance for the musical tradition that climaxed with Bach came from three things: his theology of music, his musical practice, and his own activity as a hymn writer.

Luther often expressed the conviction that music was, under God, of supreme importance. In comments he made at meal times, which eager disciples recorded as his "Table Talk," Luther several times described music as "the greatest gift of God which has often induced and inspired me to preach." In his view, God gave music to humanity as a way to impress men and women with the glory of divine gifts.

In 1542, Luther wrote a preface to a collection of funeral hymns. In it he explained what was so important about singing the truths, indeed the very words, of Scripture: "We have put this music on the living and holy Word of God in order to sing, praise, and honor it. We want the beautiful art of music to be properly used to serve her dear Creator and his Christians. He is thereby praised and honored and we are made better and stronger in faith when his holy Word is impressed on our hearts by sweet music."

A few years later, shortly before his death, Luther supplied another preface, this time to a major hymnal published in Leipzig by Valentin Bapst. It began by quoting Psalm 96: "Sing to the Lord a new song. Sing to the Lord all the earth." As Luther saw it, the great occasion for song is the work of Christ in justifying guilty sinners: "For God has cheered our hearts and minds through his dear Son, whom he gave for us to redeem us from sin, death, and the devil. He who believes this earnestly cannot be quiet about it."

One of the fruits of the believer's praise is evangelistic: Christians sing and speak about what God has done "so that others also may come and hear it." Even more, gospel truth set to music encourages those who have experienced the gospel: "Therefore, the printers do well if they publish a lot of good hymns and make them attractive to the people with all sorts of ornamentations, so that they may move them to joy in faith and to gladly sing." For Luther, nothing could fit better the sobering realities of God's law (the hidden gospel) and the comforting realities of the good news in Christ (the revealed gospel) than affective, heart-felt, joyful song.

Let my people sing

Luther's musical practice followed his theological principle. When he revised the Catholic mass for use in the new "reformed" churches, which he did very soon after his break from Rome, the new services were jammed full of music. Chorales, chants, brief liturgical compositions, hymns for daily use, and more—all were to be sung as the believer's response to the grace of God.

Luther pursued a path that lay between two significant Christian alternatives. Against Catholic tradition, Luther insisted that all the people of God sing, not just the priests and specially prepared choirs. Modern scholars like Christopher Brown have argued persuasively that congregational singing, perhaps more than any other single factor, secured the survival of Protestantism in Europe. Although Luther's own musical standards were relatively high, his great concern was what could be called the musical priesthood of all believers. Because God's grace in Christ was for all, all should sing. Because Christ made his people a royal priesthood before God, the voices of all priests (that is, all Christians) should be raised in song. With Luther began the broad, deep, and extraordinarily significant tradition of congregational hymnody that remains one of the great gifts of the Reformation to the worldwide church.

But against some of his fellow Protestants, Luther's musical practice was free rather than restricted, expansive rather than prescriptive. Other early Protestants like Ulrich Zwingli in Zurich and John Calvin in Geneva valued music and shared Luther's belief that a biblical reform of theology required a biblical reform of worship. But these Reformed leaders defined a biblical reform of worship as hewing as closely as possible to specific scriptural guidelines. Thus, since the Bible said nothing specific about polyphonic music (the complex singing of multiple lines of tunes and texts), the use of the organ, or the free composition of new hymns, their churches would use only biblical materials (usually paraphrased Psalms) as their church music. Some results of this practice, like the tunes and texts of Calvin's Geneva Psalter, made a memorable musical contribution, but it was a limited contribution.

By contrast, Luther thought it was biblical to use every form of God-honoring expression to praise the God of grace, just so long as that praise did not violate biblical truth. Lutheran church music, as a result, almost immediately created a rich culture of choir directors, choristers, organists, composers, and performers. In 1538, Luther expressed this theology in yet another preface, this time to a full collection of masses, vespers, antiphons, responsories, and hymns that was published by Georg Rhau (whose career included a stint at the Thomas Church in Leipzig where Bach would later serve). At a time when other parts of the Protestant world were narrowing musical expression, Luther boldly defended polyphony and compositional complexity as showing why "next to the Word of God, music deserves the highest praise."

To Luther, the reasoning behind this judgment was transparent: "when [musical] learning is added … and artistic music which corrects, develops, and refines the natural music, then at last it is possible to taste with wonder (yet not to comprehend) God's absolute and perfect wisdom in his wondrous work of music." Those who did not see it that way got one of Luther's characteristic brush-offs: "any who remain unaffected [by skilful polyphony] are unmusical indeed and deserve to hear … the music of the pigs."

On the free use of music for the greater glory of God, the path from Luther to Bach was direct.

A mighty fortress

Luther, the theologian who defended music and the church reformer who called for music, was also the Christian pastor who wrote music. Luther was condemned by the pope and outlawed by the emperor in 1521. Almost immediately, he then began to work on many tasks of church reform, including hymns that he wrote himself. The authoritative American Edition of Luther's Works contains 37 hymns, 24 of which were written or first published in 1523 and 1524.

Almost all of the Luther's hymns are tied closely to biblical texts. They are not poetic flights of fancy but carefully constructed vehicles for gospel teaching. His most famous hymn, "A Mighty Fortress Is Our God," is a loose, Christ-centered paraphrase of Psalm 46. Whatever the possible connections of this hymn to Luther's own spiritual journey, the editors of the American Edition are clearly correct in saying that "he did not write it to express his own feelings, but to interpret and apply the 46th Psalm to the church of his own time and its struggles." The key to Luther's interpretation is the second verse. In the translation by George MacDonald, which catches the rhythms of Luther's German better than smoother English translations, Luther affirms, "'Tis all in vain, do what we can, / our strength is soon dejected." But then comes the gospel proclamation:

But He fights for us, the right man,
By God himself elected.
Ask'st thou who is this?
Jesus Christ it is, Lord of Hosts alone …
So he must win the battle.

Luther sometimes modified existing medieval texts for his hymns, just as his tunes often cannibalized existing music (though not, as frequently repeated, from the tavern). Often he wrote hymns to accompany the seasons of the church year—as for Christmas ("From heaven on high I come to you / I bring a story good and new"), Pentecost ("Come, Holy Spirit Lord and God, / Fill full with thine own gracious good / The faithful ones' heart, mind, desire; / In them light of thy love the fire"), or Holy Trinity Sunday ("God the Father with us be … Jesus Savior with us be … Holy Spirit with us be").

Two features of Luther's hymns made them an important beginning point for what Bach would later bring to culmination. One was Luther's skillful setting of texts to tunes, in his case mostly music based on ancient church styles. Bach would write with a much fuller repertoire of modern major and minor scales but, like Luther, would also skillfully use musical conventions to mirror the meaning of texts.

The second feature was Luther's consistent focus on the mercy of God in Jesus Christ. His moving paraphrase of Psalm 130 begins with the sinner's condition: "From trouble deep I cry to thee." It moves on to a realistic assessment of that need: "If thou iniquities dost mark, / Our secret sins and misdeeds dark, /

O who shall stand before thee?" The answer comes from the heart of Luther's theology:

To wash away the crimson stain,
Grace, grace alone availeth;
Our works, alas! are all in vain;
In much the best life faileth;
No man can glory in thy sight,
All must alike confess thy might,
And live alone by mercy.

Significantly, J. S. Bach set this hymn to music several times. He did the same with other Luther hymns, some more than once.

The Lutheran legacy

By Bach's 18th century, the stream of Lutheranism was dividing into contentious currents. The Pietists stressed the need for a living theology of the heart. As part of their critique of dead orthodoxy, they called for simpler church services and simpler church music. Bach vehemently rejected these proposals, but he did embrace the Pietists' emphasis on a Christ-centered religion in which the human heart was drawn by the affections to God's love manifest in Jesus.

On the other side of the theological spectrum, Bach knew Lutheran theologians who were moving in the direction of rationalism. As children of the Enlightenment, they stressed the ability of the human mind to discover the secrets of the universe. Bach shared with these theologians a commitment to regularity and order, as the stunning precision of his compositions testified so beautifully. But he also recoiled from any rationalistic tendencies that detracted from the Bible's depiction of human sinfulness and divine redemption in Christ.

Bach was his age's most powerful exponent of Martin Luther's theology and practice. Indeed, the great modern historian Jaroslav Pelikan has asserted that Bach might be considered among the premier expositors of Luther's theology for any age. For Bach, the lodestar—musically, ecclesiastically, theologically, temperamentally, professionally—was Luther's understanding of Christ and his work. As summarized in Martin Geck's recent biography, "That [God] can be found only … through the suffering and cross of Jesus Christ and his followers, is an insight coming from Luther and one that Bach passed down in a great many different ways in the texts of his cantatas and passions but most of all in his music itself."

Theological student and writer Sarah Hinlicky Wilson recently explained why she is a Lutheran: "The only reason I follow Luther, as far as I can figure, is because Luther followed Christ. … The Jesus I get in Scripture and sermons and hymns and sacraments is there because Luther told his evangelical followers to give Jesus away freely in them." It could just as easily have been J. S. Bach who wrote these words.

Mark Noll is the Francis A. McAnaney Professor of History at the University of Notre Dame.