The Leipzig Autograph opens with a Fantasia on Komm, Heiliger Geist (Come, Holy Ghost), in organo pleno, il canto fermo nel pedale (for full organ, the chorale melody in the pedal part). The chorale itself is a German version of the antiphon Veni, Sancte Spiritus, devised by Martin Luther for congregational use. An imitative contrapuntal introduction, in which three upper voices enter in turn over a sustained pedal-note, leads to the chorale melody itself, in the lowest register, chorale phrases separated with passages of varying length for the manuals. A second treatment of the same chorale, for two manuals and pedals, is in triple metre, with a fugal subject derived from the chorale, the manuals preceding the pedal entry in each section. This extended composition ends with a particularly splendid coda. An Wasserflüssen Babylon (By the waters of Babylon), for two manuals and pedals, uses a fifteenth century chorale melody from Strasburg. .Here the chorale melody is first heard in the top part, imitated in the tenor, which itself introduces the continuation of the chorale theme. This is followed by Schmücke, dich, o liebe Seele (Deck thyself, beloved soul), much admired by Schumann and based on a mid-seventeenth century chorale, first suggested in the alto part in a contrapuntal introduction, before appearing in the soprano in augmentation, its notes prolonged. The Trio on Herr Jesu Christ, dich zu uns wend (Lord Jesus Christ, turn to us) is again based on a mid-seventeenth century chorale. Here the three contrapuntal parts interweave, the left hand entering in canonic imitation of the right over a pedal-part derived from the opening notes of the chorale. This opening figure brings, in conclusion, a pedal statement of the melody, accompanied by the continuing counterpoint of the two upper parts. O Lamm Gottes, unschuldig (O Lamb of God, guiltless, slaughtered on the Cross) is based on a Lutheran version of the Agnus Dei, O Lam Gades unschüldig, by Nikolaus Decius, an early follower of Luther. This, one of the earliest chorales, is itself derived from plainchant. The three sections of the Agnus Dei allow three different treatments of the cantus firmus, which appears first in the top part, then in the middle part and finally in the pedals. Nun danket alle Gott (Now thank we all our God) is based on a seventeenth century chorale. Counterpoint based on the melody precedes the entry of the chorale itself in the upper part, a procedure that is followed throughout, in the manner associated particularly with Bach's elder brother's teacher, Pachelbel. Von Gott will ich nicht lassen (From God I will not part) treats a sixteenth century chorale dating from 1572 in Erfurt. Here again each section of the melody, played on the pedals, is introduced by a preceding contrapuntal section derived from the hymn itself. The C major Toccata, Adagio and Fugue, striking not least in the distinctive nature of the three sections into which it falls, in form the counterpart of the three movement Italian concerto of the period. The work opens with a brilliant improvisatory prelude, display on the manuals followed by a passage for pedal solo, before more elaborate counterpoint involving manuals and pedals. There follows an Adagio aria, slowing in a concluding recitative, before a capricious fugue subject, interrupted by abrupt rests, a characteristic that naturally recurs, as the four parts enter, in descending order.

Nunkomm, der Heiden Heiland (Now come, Saviour of the Heathen) appears in three versions. The chorale on which it is based is Martin Luther's adaptation of the original Ambrosian hymn Veni Redemptor gentium. The first of these, for two manuals and pedals, opens with the first measures of the chorale theme in the tenor, imitated at once in the alto register, over a constantly moving pedal bass. The melody is then elaborated in the upper part to form an ornamented line. The second treatment of the chorale is in the form of a Trio, three melodic lines, one for each hand and one for the pedals. Here a contrapuntal imitative opening by the two lower parts is followed by the appearance of the ornamented chorale theme, to which the two lower parts provide a postlude in conclusion. The third version of Nun komm, der Heiden Heiland is described as in organo pleno, il canto fermo nel pedale (for full organ, with the chorale melody in the pedal part). An introductory contrapuntal passage derived from the chorale leads to the solemn appearance of the chorale itself in the lowest register, successive pedal entries preceded by similar prefatory passages. The canonic variations on Vom Himmel hoch (From Heaven on high) were apparently written in 1747 and offered by Bach when he was admitted to the polymath Lorenz Christoph Mizler von Kolof's Correspondierenden Societät der Musicalischen Wissenschaften (Corresponding Society of the Musical Sciences). Bach was the fourteenth of a membership limited to twenty scholars and musicians, including, among those now better remembered, Telemann and Handel. The Christmas chorale by Martin Luther first appears in the pedal part of a Canon at the Octave that involves the two upper parts in such canonic imitation. The cantus firmus is again heard in the pedals, in the second Canon at the Fifth, followed by the chorale melody itself in canon at the sixth and in inversion in the lower voice, accompanied by a moving pedal part. Once the chorale has been heard in this form, Bachadds a canon at the third, with the upper part entering first with an inversion of the melody. A canon at the second follows, between the pedal bass and tenor in inversion, and then, at the ninth, between a pedal inversion and the top voice. This varied treatment of the cantus firmus itself leads to a Canon at the Seventh between the pedals and tenor. A Canon in Augmentation sets an augmented tenor part in canon with a more rapid upper part, with the steadier chorale melody introduced by the pedals. The Canonic Variations constitute a remarkable technical and musical tour de force.