One defining characteristic of late twentieth- and early twenty-first century musical culture has certainly been a devotion to the reconstruction of the performance traditions of the past.1 Defunct instruments like the viola pomposa have been eagerly researched, and their historical playing technique scrupulously recreated.2 Everything from the proportions of Bach's fingers3 to the cost of his candles4 has been examined in an attempt to understand the atmosphere and circumstances in which his music was made. While many such pursuits have taught us much about the music's genesis and relevance, sometimes the result has been an enthusiasm-induced myopia that has kept us from seeing the true possibilities. For example, a generation of harpsichordists played Bach on their copies of late eighteenth-century French harpsichords before recognizing that the eighteenth-century German harpsichord was a different animal altogether--indeed, one that has yet to be fully revived. And it has only been in very recent years that the not unimportant role played by the early German piano in Bach's late life has come to be appreciated and explored. This state has largely been caused by a simple deflection: the mere recognition of a larger truth (e.g., Bach played the harpsichord and not the modern piano) has sometimes been sufficient distraction to urge us down a side-winding path toward the most convenient solutions.
The same can be said of the situation with Bach's keyboard continuo instruments. Early on in the revival of historical performance practices, it was recognized that a keyboard instrument was needed to reinforce the bass and fill out the harmony in Bach's music. Yet the full extent to which the chosen keyboard instrument can influence the total sonority of a work was given little attention. In fact the debate quickly degenerated into the essentially unimportant and uninteresting argument of whether to use organ or harpsichord in Bach's vocal works.5 Once the dust settled over this question however, few musicians felt compelled to look much further into the matter. Among the groups that are currently recording Bach under the umbrella of historically informed performance, not one can claim to be truly faithful to the total body of historical literature on the sonority of Bach's keyboard continuo.
The first question to ask, then, is: what instruments were being used for continuo playing in Bach's time? It might surprise many to learn that there is very little evidence of box-shaped portable organs6 resembling our continuo organs in use in Central Germany in the eighteenth century. Bach certainly knew very small organs. There was a four-stop organ as well as a regal at St. Michael's in Lüneburg, where Bach went to study in 1700.7 In Leipzig there was a harpsichord and a small organ in an auditorium adjacent to the Cantor's office in the Thomasschule,8 and Bach used a small organ built in 1628 and tuned to choir pitch at St. Paul's in Leipzig when he accompanied the eight-part motet Der Geist hilft unsre Schwachheit auf (BWV 226) in 1729.9
None of these organs still exists, but we do have some idea of what was considered an average small organ at the time. Positiv organs were sometimes found in a private house or a palace chamber, but also in churches and church rehearsal rooms. Standing anywhere from seven to ten feet tall, and containing anywhere from four to eleven stops, these instruments were distinguished from larger organs by two outstanding features: they had only one manual, and they lacked a Pedal division. Such organs may or may not have had an 8' Principal.
A few organs of this size by Bach's friend Gottfried Silbermann still exist. The organ presently in the undercroft of the Cathedral in Bremen, Germany, was originally conceived for a small church in Etzdorf bei Roßwein in 1745. (See Illustration page 20; the Pedal in the photograph is a later addition.) The instrument contains eight stops and numerous registration possibilities:
8' Rohrflöte
4' Principal
4' Flöte
3' Nasat (treble only)
2' Octava
11/2' Quinta
1' Sifflöt
Sesquialtera (treble only)
A positiv organ by Silbermann from 1728 still survives in Tiefenau. It contains nine stops, including an 8' Principal.
8' Principal
8' Gedackt
4' Octav
4' Rohrflöte
3' Nasat
2' Octav
11/3' Quinte
1' Sifflöte
Zimbel II
There is still one small organ in existence definitely used by Bach for continuo: the small Zacharias Hildebrandt organ in the village church of Störmthal. On November 2, 1723 Bach dedicated this organ with a performance of his cantata Höchsterwünschtes Freudenfest (BWV 194). The original specification was:10
Manual
8' Principal
8' Gedackt
8' Quintadena
4' Praestant
4' Rohrflöte
3' Nasat
2' Octave
13/5' Terz
11/2' Quinte
1' Sifflöte
Mixtur III
Cornet IV
Pedal
16' Subbaß
16' Posaune
For the most part, however, organ continuo accompaniments would have been played on a large instrument. During his time in Weimar, Bach had at his disposal an organ of twenty-four stops in a gallery high above the altar in the castle chapel. When desired, a sliding unit could be engaged to close off the gallery's opening into the main body of the chapel, thus creating a separate music rehearsal chamber containing (besides the organ) a harpsichord, a spinet, and other musical instruments. In St. Thomas Church in Leipzig, the organ Bach used would have been most likely the three-manual, thirty-six stop organ in the rear gallery, or, for special effects (such as in the St. Matthew Passion), the two-manual, twenty-one stop swallow's nest organ that was situated high above the crossing.
With all of these resources at the continuo player's fingertips"organs small, medium, and large"it is no surprise that continuo players were creative in their continuo realizations. Before delving into some of the more impressive registrations, it is would be worthwhile to consider the stop most commonly heard in continuo realizations today, the Gedackt 8'. It is true that the Gedackt 8' was often regarded as the basic continuo stop. Indeed, Bach's colleague in Leipzig, Johann Adolph Scheibe, specified that one should use a Gedackt 8' in soft arias and recitatives,11 and Bach himself asked for a Stillgedackt 8' for his organ in Mühlhausen for playing concerted music.12 Nevertheless, an 8' Gedackt on Bach's instruments in Weimar or Leipzig would have had a substantially more supportive voice than the very small-scaled stops found on the average trunk organ.
With all of this in mind"the size of the instruments used by Bach and the presence their larger-scaled stops must have made"it is surprising that virtually no modern conductors have ventured beyond the now-traditional use of the four-to-six-stop trunk organ. One Dutch musician who is currently traversing the Bach cantatas in the recording studio acknowledges that the effect of the trunk organ used in his performances is remarkably different than that of the organs used by Bach.13 Yet he justifies his decision by explaining that the trunk organ offers greater convenience in tuning and logistics"advantages, he says, that must outweigh the loss in sonority. What is bothersome about this argument is that it admits to purchasing convenience at the cost of musical effect. Indeed, where else does an historically conscientious approach to performance begin than with an attempt to use the right instrument?
The present preference for the trunk organ may be no more than a symptom of a lingering neo-baroque reticence to trust the evidence that has come down to us. A simple example will explain. In his proposal for the rebuilding of the organ in Mühlhausen in 1708 Bach proposed a manual Fagotto (Bassoon) 16' "that sounds delicate in concerted music."14 Ton Koopman confessed that he has tried using a 16-foot reed as a continuo support, but that it so seriously compromised the dynamic flexibility of the continuo group that he found it impractical. The truth is, however, that evidence of the use of a Bassoon 16' in continuo among Bach and his contemporaries is simply too great to ignore, no matter how puzzling it may seem, at least initially. For example, the organ builder Heinrich Gottfried Trost, whose organ in Altenburg Bach played and admired in 1739, stated that the Bassoon 16' "can be well used in concerted music."15 As with all historical registrations, however, the effectiveness of the use of a Bassoon 16' as a continuo stop will largely depend on the texture and character of the music in which it is used. Bach gives us no clue as to his intentions, but his contemporary Johann Friedrich Walther stipulated that the Bassoon 16' in a 1732 Joachim Wagner organ in Berlin was useful specifically for playing running basses in continuo.16 The experience of using such a stop in faster-moving basses might teach us a great deal about what sort of instrumental playing and ensemble that continuo stop supported. The result could well be revelatory, prompting a reevaluation of how we expect Bach's music to sound. This sort of evidence confronts us once again with the chicken-and-egg question that has been part of the performance practice argument from the very beginning: Were the tools at Bach's disposal an inspiration or a limitation? A deeper look at the evidence will convince us to view these tools as not only an inspiration, but an invitation as well.
Let us examine some alternatives to the trunk organ's small-scaled 8-foot Gedackt. Jacob Adlung recommends accompanying a soft voice with a single flute, such as a Gedackt 8' or a Quintatön 8'. According to Adlung, one can also use a Principal 8' or a Gemshorn 8' for difficult recitatives, or if the singer is insecure. Running passages on the manuals, however, can be played with Violdigamba 8' with or without a Principal. Ideally, the organist should have one or two flute stops drawn on one manual, and a Principal on another manual, in order to facilitate quick dynamic changes.17 Unlike the trunk organ, which relies on upperwork for color, sources such as Adlung clearly called for great color flexibility at the eight-foot level.
Adlung then adds that the organ must play out in chorales, especially since chorales usually involve full choir and congregation. For chorales he recommends Principal 8', Oktave [4'?], or Quinte 3'.
The Principal 8' seems to have been a valued continuo stop altogether. Among other sources close to Bach that mention the importance of the Principal 8' as a continuo stop are Walther,18 Gottfried Heinrich Stölzel,19 Christoph Gottlieb Schröter,20 and Johann Samuel Petri.21 Supported by a fuller-sounding continuo, even small ensembles will be encouraged to play with the sort of full-throated, forceful sound that we know so well from German Baroque organs like those of Arp Schnitger and Gottfried Silbermann.
With only a handful of stops, the skilled organist at an organ of some size then had the resources to play a wide variety of dynamics, at the same time making a substantial contribution to the overall color of the ensemble. For example, in 1738 Gottfried Heinrich Stölzel required the following stops for concerted music at the large two-manual Trost organ in Altenberg:
Principal choir with mixtures
Quintaden 16' and 8'
Bordun and Gedackt 8'
Gemshorn 4'
Nasat 22/3'
Subbaß, Violonbaß22
While Stölzel used a Principal chorus, the use of higher and more powerful Principal stops is not always sanctioned. Adlung notes the habit in village churches of accompanying the choir at the end of pieces with full organ, adding that one does not hear the singers or instrumentalists well.23 Petri warned against using reeds, mixtures, or mutations in continuo.24
Gottfried Heinrich Stölzel named the stops Subbaß and Violonbaß among his continuo stops, and this fact reminds us of an important function of the continuo, and one that is completely unfulfilled by the use of a trunk organ. The continuo player is not just to fill out the harmony, but should make a substantial contribution to the overall sonority of the bass line itself. A number of sources mention the use of 16-foot manual stops to strengthen the bass. These include:
1. Jacob Adlung, who recommends Quintatön 16' or Bordun 16', even strengthened by an Oktav and a quiet 8-foot, especially if one is playing staccato.25
2. Heinrich Gottfried Trost, who recommended Flute traverse 16' und Spitzflöte 8' (as found on the organ at Altenburg).26
3. Daniel Gottlob Türk, who stipulated that "one can still lend to the bass the needed depth and emphasis by means of one or two [!] 16-foot registers in the Hauptwerk. . . ."27
4. Johann Gottfried Walther, who stated that Gedackt 16, 8, 4 "are the most accommodating for the general bass."28
While many of these sixteen-foot stops are manual stops, clearly organists were called upon to double the bass line in the Pedal as well, another practice virtually ignored in modern performances. The number of contemporary sources that describe playing the bass line on the Pedal is simply overwhelming. Petri writes:
. . .Im Pedale ein 16füßiges [ziehen], oder wenn sie nicht stark sind, zwey: und höchstens noch ein 8füßiges Principal zum forte, und zum äußersten forte noch ein 4füßiges Principal, welches jedoch besser wegbleibt, es wäre denn, daß gar keine Violons, Violoncelli und Fagotts mitspielten, und der Organist den Baß allein machen müßte, wie auf dem Lande. . . .
. . .In the Pedal, [draw] a 16', or, if the [Pedal stops] are not strong, two, and at least an 8-foot Principal for the forte, and for extreme forte a 4-foot Principal as well, which is better left out if there are no violones, cellos, and bassoons playing along, and the organist must play the bass alone, as is done in the country. . . 29
Türk states the case clearly:
Daß aber die ganz tiefen Register, z. B. Posaune 32 und 16 Fuß im Pedale nicht einmal geschwind ansprechen, und noch überdies mehr ein Getöse machen, als einen deutlichen Ton angeben, lehrt die Erfahrung. Außerdem muß man freylich, ohne einen hinlänglichen Grund, das Pedal nicht weglassen. . .
Experience teaches that the very low stops such as Posaune 32' and 16' in the Pedal do not speak quickly, and furthermore [they] produce more of a racket than a clear tone. Otherwise one must certainly not leave the Pedal out without sufficient reason. . . . 30
Sufficient reasons to leave the Pedal out are explained in a footnote: when the violone (i.e., an instrument playing at sixteen-foot pitch) drops out, when there is a senza basso indication in the score, when a short passage is repeated an octave higher, and when the bass pauses in fugues. In these cases the bass should be played only on the manuals without a 16-foot stop.
Sources closer to Bach include Johann Friedrich Walther (Pedal Principal 16 "gravitaetisch," used in large ensembles; Pedal Violon 16 "sehr tief und kräftig"),31 Gottfried Heinrich Stölzel32, and Friedrich Eberhardt Niedt (who recommends Pedal 16', even a reed 16', to make the Pedal clearer).33
Indeed, many sources state that Pedal stops need not be restricted to Principals and Flutes. In 1719 E. Lindner ordered a reworking of the Pedal Posaune at the famous Silbermann organ in Freiberg to make it more suitable for use in concerted music.34 Just how such a stop could be used in continuo is difficult to imagine, at least until one considers a work like Ein' feste Burg ist unser Gott (BWV 80). The manuscript of the Leipzig version (a copy by J. C. Altnickol from 1744) specifies a double continuo: Violoncello e cembalo for the first bass (i.e., 8-foot), and organ and violone for the cantus firmus bass (i.e., 16-foot).35 The manuscript specifies "Pedal Posaune 16 Fuß." What performers today would seek to find an instrumental, choral, and acoustical solution to justify such an overwhelming registration?
Perhaps all that has been discussed here can be summed up and amplified best by a remarkable source of information on continuo practice that is very little known in the English literature on the subject. That it is so little known is lamentable especially because it may well be the most telling witness to the continuo registrations practiced by Bach and his associates in Leipzig.
The registrations by Christoph Gottlieb Schröter (1699-1782)36 summarized at the end of this article provide a glimpse of the sort of continuo registrations used on Saxon organs in Bach's immediate circle. Schröter and Bach knew each other well. Like Bach, Schröter was a member of Lorenz Christoph Mizler's Society of Musical Science in Leipzig. When Bach's music came under attack 1749 by the critic Scheibe, Bach turned to Schröter, a friend of some thirty years,37 to muster a counterattack in the musical press. Undoubtedly, Schröter was intimately familiar with Bach's music as well as with Bach's performance style. Though these registrations were not published until the 1770s, they were recorded in the early 1750s, at which time Schröter was organist in Nordhausen,38 a city about halfway between Leipzig and Göttingen, where he played a sizable organ built in 1729 by Johann Georg Papenius.39
There are several extraordinary things to note about these registrations, including:
1. The frequent use of more than one 8-foot stop together.
2. The tendency to avoid stops higher than 4-foot for chordal, i.e., non-solo accompaniments.
3. The practice of combining quick-speaking stops (such as a Flute) with slow-speaking stops (such as a String).
4. Dynamic flexibility, largely achiev-ed by manual changes.
5. The general size of the registrations, including those suggested for recitatives and ariosi (with the left hand on the Hauptwerk).
6. Color extended even to recitatives, where four-foot stops are included.
7. Varied registrational color according to the obbligato instrument used (oboe, flutes, muted strings).
8. The simply fantastic registrations for organ obbligato.
There is still a lot to investigate in the matter of continuo sonority in Bach's music. For example, there is the question of pitch. While many organs were tuned to choir pitch (Chorton A = 460-490), many had certain stops tuned to the lower chamber pitch Kammerton A = 390-415)40, giving them a handful of stops suitable for accompanying instruments tuned to chamber pitch.41 Some organs even had entire keyboards tuned to different pitches, or a manual division that was playable at either Chor- or Kammerton.42 And then there is the entire question of harpsichord sonority, including the use of a 16-foot register in continuo accompaniment. And then there are fortepianos, Lautenwerke, Geigen-Claviere, keyed pantaleons, and any number of other instruments awaiting a willing and wondering ear to explore how rich and how varied the sonority of Bach's continuo realizations must have been.43
It has not been the intention of this article to vilify completely the use of trunk organs today; indeed, their usefulness and often their beauty are undeniable. Nor is there any desire to throw verbal cold water on the vital music making of great musicians like Ton Koopman, Philippe Herreweghe, Masaaki Suzuki, Nikolaus Harnoncourt, or Gustav Leonhardt. It is not the trunk organ's existence, but its pervasiveness that is so limiting, serving as an ever-present reminder of our anti-baroque insistence that the continuo must somehow live in the shadow of the real music. Perhaps it is time for us as continuo players to step forward from behind the little box and become a full voice in the total sonority of Bach's music.
After playing a prelude, the organist takes off all stops except the following:
Hauptwerk: Principal 8', Gemshorn 8', Viola di Gamba 8', Octava 4'
Rückpositiv: Quintadena 8', Gedackt 8', Flöte 4', Rohrflöte 4'
Brustpositiv: Gedackt 8', Gedackt 4', Violetto 4'
Pedal: Principal 16', Principal 8', Violon 16'
Couple Hauptwerk to Pedal
Accompany full chorus and orchestra on the Hauptwerk. For passages with orchestra alone, play with the right hand on the Rückpositiv.
For echo passages, leave out the Pedal and play with the right hand on the Rückpositiv.
For various kinds of recitatives:
1. Use the same registration above, removing the Pedal coupler and the Hauptwerk Octava 4'.
2. Use the registration above, playing on the Hauptwerk with the left hand, and on the Rückpositiv with the right hand.
Aria with oboe obbligato accompanied by violins:
Hauptwerk (left hand): Principal 8', Gemshorn 8', Viola di Gamba 8'
Rückpositiv (right hand): Quintadena 8', Gedackt 8', Rohrflöte 4'
Pedal: Principal 16', Violon 16', Hauptwerk to Pedal
Aria with one or two flutes and muted strings:
Hauptwerk (right hand): Flauto traverso [8'], Gemshorn 8'
Rückpositiv (left hand): Quintadena 8', Gedackt 8'
Pedal, uncoupled: Violon 16', Principal 8'
Mournful aria with a single solo instrument (e.g., oboe) and organo concertato, without other accompanying instruments:
Hauptwerk (left hand): Viola di Gamba 8', Gemshorn 8'
Rückpositiv (right hand): Vox humana 8', Quintadena 8'
Pedal, uncoupled: Violon 16', Principal 8'
Aria with more than one solo instrument, organo concertato, and other accompanying instruments:
Hauptwerk (left hand): Principal 8', Gemshorn 8', Viola di Gamba 8'
Rückpositiv (right hand): Quintadena 8', Gedackt 8', Rohrflöte 4', Principal 4', Octava 2'
Pedal, coupled: Principal 16', Violon 16', Principal 8'
Notes
1. This article began as a lecture delivered at the Improvisation Symposium held at Eastern Michigan University in November 2000, and was sponsored by the Ann Arbor Chapter of the American Guild of Organists. I am grateful to Dr. Pamela Ruiter-Feenstra, Professor of Organ at EMU, and the Ann Arbor Chapter of the AGO for affording me the opportunity to delve into these matters.
2. Ulrich Drüner, "Violoncello piccolo und Viola pomposa bei Johann Sebastian Bach: Zu Fragen von Identität und Spielweise dieser Instrumente" Bach Jahrbuch (1987), pp. 85-112.
3. Quentin Faulkner, J. S. Bach's Keyboard Technique: A Historical Approach (St. Louis: Concordia, 1984), p. 18.
4. Christoph Wolff, Johann Sebastian Bach: The Learned Musician (New York: Norton, 2000), p. 540.
5. These arguments were finally given a rest by Lawrence Dreyfus, Bach's Continuo Group: Players and Practices in His Vocal Works (Cambridge: Harvard University Press, 1987).
6. Also referred to as trunk organs, positive organs, continuo organs, Kastenorgeln, or Truhenorgeln.
7. Wolff, Johann Sebastian Bach, p. 477.
8. Ibid, p. 250.
9. Ibid, p. 316.
10. As the organ survives today, only the specification of the Pedal has been slightly altered.
11. " . . .da man hingegen bey schwachen Arien und bey Recitativen allein des Gedackt acht Fuß gebrauchen darf." See J. A. Scheibe, Critischer Musicus (Leipzig: 1745), p. 415.
12. "Stillgedockt 8f., so da vollkommen zur Music accordieret". See Frans Brouwer, Reinoud Egberts, Hans Jansen, Paul Peeters, Maurice Pirenne, editors, Bach's Orgelbüchlein in nieuw perspectief (Utrecht: Hogeschool voor de Kunsten, 1988), p. 172ff. The term Music as used in this context most certainly refers to concert music. Gott-fried Silbermann, in his proposal for the organ in Freiberg, described his Gedackt 8 as being gently voiced for concerted music ("Gedacktes 8 Fuß zur music liebl. intoniert"). See Frank Harald Greß, Die Klanggestalt der Orgeln Gottfried Silbermanns (Frankfurt and Wiesbaden: Bochinsky and Breitkopf und Härtel, 1989), p. 132.
13. Ton Koopman, "Aspekte der Aufführungspraxis" in Christoph Wolff and Ton Koopman, Die Welt der Bach Kantaten (Stuttgart and Weimar: Bärenreiter and Metzler, 1996), vol. 1, p. 222.
14. ". . .in der music delicat klinget." See Brouwer, et. al., Bach's Orgelbüchlein, p. 172ff.
15. Quoted in Ewald Kooiman, Gerhard Weinberger, and Hermann J. Busch, Zur Interpretation der Orgelmusik Johann Sebastian Bachs (Kassel: Merseburger, 1995), p. 163.
16. See Brouwer, et. al., Bach's Orgelbüchlein, p. 181. The organ was in the Garnisonskirche. Jacob Adlung also mentions the Bassoon's usefulness as a continuo stop. See J. Adlung, Anleitung zur musikalischen Gelahrtheit, Erfurt, 1758, p. 386.
17. Adlung, Gelahrtheit, p. 386ff.
18. Principal 8 "unter dem Tutti einer Music." See Brouwer, et. al., Bach's Orgelbüchlein, pp. 181-82.
19. Specifically on the Trost organ in Altenburg. See Greß, Klanggestalt, p. 132.
20. Christoph Gottlieb Schröter, Deutliche Anweisung zum General-Baß, Halberstadt 1772, pp. 187-90.
21. Johann Samuel Petri, Anleitung zur praktischen Musik, 2. Auflage (Leipzig, 1782), p. 169ff.
22. Greß, Klanggestalt, pp. 132-33.
23. Adlung, Musica mechanica organoedi (Berlin, 1768), p. 171ff.
24. Petri, Anleitung, p. 169.
25. Adlung, Anleitung, p. 386. Elsewhere Adlung even suggests using a Principal 16'. See Musica mechanica organoedi, p. 171ff. One assumes the staccato reference is because 16-foot stops alone generally do not speak quickly enough to perform staccato notes successfully.
26. Kooiman et. al., Interpretation der Orgelmusik, p. 163.
27. Daniel Gottlob Türk, Von den wichtigsten Pflichten, (Halle, 1787), p. 156.
28. ". . .so zum G[eneral B[aß] am bequehmsten ist." See Johann Gottfried Walther Musikalisches Lexicon (Leipzig, 1732), p. 275.
29. See Petri, Anleitung, p. 169ff.
30. Türk, Pflichten, pp. 156-57.
31. Brouwer, et. al., Orgelbüchlein, p. 183.
32. Greß, Klanggestalt, pp. 132-33.
33. Friedrich Eberhardt Niedt, Musikalische Handleitung (Hamburg: 1710-12).
34. Greß, Klanggestalt, p. 132.
35. Dreyfus, Bach's Contiuo Group, pp. 15-16.
36. Christoph Gottlieb Schröter, Deutliche Anweisung zum General-Baß, Halberstadt 1772, pp. 187-90.
37. Wolff, Johann Sebastian Bach, p. 423.
38. Julie Ann Sadie, Companion to Baroque Music, Berkeley: University of California Press, 1990, p. 192.
39. See Johannes Schäfer, Nordhäuser Orgelchronik (Berlin: Buchhandlung des Waisenhauses, 1939), pp. 54-56.
40. See Daniel R. Melamed and Michael Marissen, An Introduction to Bach Studies (Oxford: Oxford University Press, 1998), pp. 142-45, for an introduction to this thorny issue.
41. Adlung stipulates just which stops are to be tuned to Kammerton: In the Pedal at least the Subbaß and in large churches an 8-foot and a 16-foot flute as well. In the Positiv the Musikgedackt, in the Hauptmanuale "as much as is needed for an obligato bass" ("so viel, als ein obligater Baß nöthig hat"). He then goes on to say that the castle organ in Merseburg has the following stops in Kammerton: Gedackt 4', Principal 4', Grobgedackt 8', Pedal Subbaß 16' and Octav 8'. See Adlung, Gelahrtheit, p. 386. The Wagner organ in the Cathedral in Brandenburg had a Gedecktes 8 Fuß Cammer Thon in the Obermanual. See Andreas Kitschke, Die historische Wagner-Orgel im Dom zu Brandenburg/ Havel (Passau: Kunstverlag-Peda, 1998), p. 15.
42. The Johann Michael Röder organ built 1722-1725 for St. Magdalena in Breslau had a Pedal Kammerbass 16' and Kammerbass 8' (tuned to Kammerton), and Chorbass 16', tuned to Chorton. The entire Unterclavier could be played in either Chorton or Kammerton.
43. See John Koster, "The Quest for Bach's Clavier: An Historiographical Interpretation," Early Keyboard Journal 14 (1996), pp. 65-84.
