Introduction
The modern "orgelbewegung" organ revival has cultivated as a norm the German neo-Baroque organ, using stopped or partly stopped flutes as foundations at 8' and 16' pitch in small instruments. This practice has been given such authority that many organists do not question it; but this type of organ is only one style among many. Neither it nor any other design ought to be raised to the level of dogmatic acceptance. The multiple foundation stops found in the best nineteenth-century organs represent the continuation of a tradition which had been already established in the Baroque period. A perception of the history of the organ which does not ignore the nineteenth century should lead us to see that multiple foundation stops in the manuals are consistent with eighteenth-century practice and not the exception.
In this paper, the presence of such stops in important examples is noted and described. It is observed that some organs of the eighteenth- and nineteenth-century have an extraordinarily cohesive blend of stops in various combinations. An acoustic theory is put forward to explain the reason for this blend or its absence. This theory states that stops are able to blend when harmonics are present in the unison tone which duplicate the fundamentals of the upper pitches. It is also observed that stopped pipes used as foundations cannot provide these harmonics.
A most important application of this point of view is that the pedal of a small organ may be based upon a 16' open subbass, not the traditional stopped bourdon. Several organs are cited which demonstrate this practice, from the eighteenth, nineteenth, and twentieth centuries. It is noted that in the manual divisions the Italian organs used 8' open pipes as foundations through their entire history; however, the Italian organ has generally been ignored as a model for small instruments. It is concluded that the exclusive use of stopped pipes as fundamentals in small organs should be reconsidered. The extensive use of stopped flutes represents a restricted, national style which ought not assume the role of a universal model. Open pipes blend better and make the tone more cohesive. We should question accepted norms of "organ design" and revise them in favor of those traditions which include the use of open pipes to provide the fundamental tone. This will allow organs in churches to be most effective at their primary role, to provide a foundation for congregational singing.
Historical Background
With the neo-Baroque organ revival, organ scholarship blossomed and has resulted in the construction of new instruments re-creating stop lists that belong to specific national or regional styles of organ building. These instruments reflect earlier times and their respective literatures. These trends were transmitted remarkably quickly to North America. This was accomplished primarily by North American scholars studying abroad and by European specialists teaching in North America. Some years later these same trends appeared in other English-speaking countries such as Australia. This organ revival filled a particularly heartfelt need resulting from a discontinuity of the traditions of organ building which was most evident in the "orchestral" and theatre organs of the 1920s.
It is not a simple matter to establish exactly why traditional concepts of organ building were abandoned, but if any one cause is to singled out, it must be that certain types of electric action made possible the use of the same pipes at two or more pitches (unification) or on two or more keyboards (duplexing)1. These purely technical devices of organ design, made in the interests of a certain type of economy, made it impossible to voice the organ so that its stops could blend. This break with the traditional concepts of organ voicing set the stage for rediscovery of older traditions, rather than allowing a normal evolution of organ design. When it became obvious that something had been lost through neglect, there had to be a "revival" so that whatever it was that had been lost could be reinstated.
Unification and duplexing destroyed the blending ensemble so thoroughly that, despite the effects of the organ revival movement, we have not yet recovered the consciousness that the stops of an organ must truly blend together. The result is a genuine anachronism: the separate stops of many modern organs refuse to blend, while there still exist a few forgotten nineteenth-century instruments, the best from their time, which preserve the ability of every one of their stops to blend with every other. While the "revival" organs do not have unification or duplexing, often they show an indifference to blend that can be traced to the disastrous lapse of sensitivity in voicing that unification and duplexing have left as their aftermath.
New Organs in North American and Australia
One result of the organ revival has been the crystallization of the neo-Baroque stoplist into a norm for the construction of new organs. But because a "revival" resurrects an older stratum of the culture which has already passed away, the organ revival reflects the specific requirements of a style of organ playing which is no longer in an active phase of development. The "revival" organ often reflects the general requirements of eighteenth-century organ playing and the specific demands of German Lutheran organ literature. It is now customarily imposed upon English-speaking regions of the world, regions which possess traditions and literatures vastly different from those of an eighteenth-century culture. This neo-eighteenth-century norm presents itself virtually as a doctrinal system, often assuming a degree of authority that is insisted upon in the same way that a theological principle may be insisted upon.
The North American adoption of the neo-Baroque organ design was a "marriage of convenience" to aid the recovery from the theatre organ debacle and its after-effects. It has persisted quite a bit too long. Now we are being called to take up once again the historical evolution of the instrument.
The objective of the author is to develop a theory of organ registration and specification that does not reflect the demands of any national or regional style. Instead, it is a theory of organ specification which proceeds from an acoustic basis. It is intended to fulfill the needs which we find in English-speaking churches at the end of the twentieth century. Like the ancient eclectic philosopher, we have selected such doctrines as please us from every school. Our music borrows freely from many sources, and is not exclusive to any one tradition.
The Nineteenth-Century Contribution
In Australia, New Zealand, Canada, the United States and Europe, there still exist nineteenth-century organs virtually untouched or relatively intact, preserving a tradition of organ building which has largely been lost in the major population centers. A number of these organs are being rehabilitated and it is no longer fashionable to take away their original characteristics. Restorations, not rebuilds, are becoming more common. An example is the organ formerly of St. Stephen's Roman Catholic Cathedral, Brisbane, built about 1880.2 This old instrument survived the rebuilders because of the happy circumstances of benign neglect. Fortunately, there was not enough money available to replace or "modernize" it.
This organ features tracker action, low wind pressure, bright reeds, and clear but not loud upper work. Everything rests upon a foundation of several unison stops and all reasonable combinations of two or more stops can be depended upon to combine into a blend of great cohesion. These factors suggest that this organ represents an evolution of the traditions of organ building which had been current during the century before. Though the sound is quite different from a Baroque organ, there is no radical departure from the eighteenth-century traditions, but rather a continuity with them. The result is that the music of both Bach and Brahms sounds very comfortable on this instrument.
The Great manual of this organ corresponds almost exactly to the Baroque ideal in the plan of the stops and their assignment at various pitches. The character of the stops has changed according to the styles of the period, but the essential design of the ensemble is preserved. As a model for comparison the specification of the Great manual is given from the Löfsta Bruk organ of 1728 by the Swedish builder Cahman,3
It is apparent from nineteenth-century examples (for instance, by E.&G.G. Hook and others in Canada and the United States), that tracker action, low wind pressure, bright reeds, upper work and mixtures were all elements of organ building that had been carried over into the nineteenth century from the eighteenth century. What about the multiple unison stops? Do these represent a "Romantic" tradition only, or are they an element that was being carried over from the Baroque period into the Romantic era? In both organs cited above, there is an open 8' to serve as the foundation for the ensemble, a wide-scaled flute to give it depth, and a third 8' stop to contribute the harmonics necessary to bind the ensemble together. In the eighteenth century, these harmonics were provided by the Quintadena, meant to act together with the Principal 8'. In the nineteenth century the Diapason had a wider scale than the eighteenth-century Principal. Therefore the third 8' stop, which must contribute the binding harmonics to the ensemble, is the Gamba, a string-toned stop of such wide scale in this organ that it is very much like a narrow-scaled Violin Diapason.
If we emphasize the similarity of the two stop lists rather than their differences, we can obtain a better view looking back at the eighteenth century and also looking forward to the twentieth century. It is possible to theorize on specifications which can accommodate not only the music of Buxtehude and Bach, but also the other portions of the literature, such as that by Dupré or the French symphonists, which have grown out of the traditions of the nineteenth century.
The Difference between "Registration" and "Specification"
Organ specification is not the same thing as organ registration. A specification is a list of the various stops of which a particular instrument is composed. Registration is the setting down of certain combinations of stops in order to produce a desired effect. In a given organ, there is a specification of stops which should combine together to give the instrument a distinctive musical formulation, which we call "ensemble", all the parts of which match together and harmonize. From this specification, an indeterminate number of registrations may be drawn, which express various facets of that distinctive musical ensemble. The full organ registration should be equivalent to the specification of the instrument less certain stops intended for special effects.
The specification of an organ should be built up, not to make combinations, but rather to provide for maximum blending of stops. Blending stops may be pursued in two directions--vertically (8', 4,' 22/3', 2' etc.) and horizontally (8' + 8', 4' + 4'). The 8' and 4' accompaniment stops, which are flutes, should blend horizontally with the principal chorus. How often have students been admonished not to combine stops of the same pitch, because of tuning problems! In nineteenth-century organs, the 4' flute was usually open or harmonic and combined naturally with a 4' principal, rather than beating against it. Both the Brisbane organ and the Löfsta Bruk organ present an open 4' flute capable of combining with a 4' principal. This is not a new characteristic making its first appearance in the nineteenth century.
The reed stops should blend horizontally with both flutes and principals. There ought to be maximum harmonic reinforcement between the reeds and flues--that is, there should be no sour off-harmonics in the reeds. Therefore, full-length reeds are to be preferred to half-length reeds, which have a peculiar harmonic series with flat ninths and so on.
Finally, at least one mixture stop may contain a tierce, in order to assist in the blend with the reeds. This characteristic occurs in both the Brisbane and the Löfsta Bruk organs. We can see from the above, that specification is the organ builder's art. Specifications should not be made up to encompass the most possible registrations. Rather, the various registrations should be derived from each organ's individual specification. The specification of a particular instrument should be set up to secure the maximum possible blend, both in the horizontal and vertical directions. From a specification may be derived two contrasting types of classes of registrations: blending registrations and non-blending registrations. These are defined and discussed below.
The Harmonic Overtones of Open and Stopped Pipes
It is well known that all organ pipes produce composite tones consisting of various harmonic partials.4 The partials of 8' open pipes which concern the present theory of registration are these:
First partial = Fundamental
Second partial = Octave = Fundamental of 4' stops
Third partial = Quint = Fundamental of 22/3' stop
Fourth partial = Double octave = Fundamental of 2' stop
Fifth partial = Tierce = Fundamental of 13/5' stop
The fundamentals of the 4', 22/3', 2' and 13/5' stops all reinforce harmonics already present in tone of the open 8' stops. Therefore the 4', 22/3', 2' or 13/5' stops will blend acoustically with the open 8' stops.
The stopped pipes, in contrast, behave very differently. They emphasize only the odd partials. Those partials of stopped pipes which characterize their tone are these:
First partial = Fundamental
Third partial = Quint = Fundamental of 22/3'stop
Fifth partial = Tierce = Fundamental of 13/5' stop
These stopped pipes form strong blends with mutation stops, but not with the octave-sounding registers of the principal chorus.
"Blending "and "Non-Blending" Registrations
"Blending" registrations are defined here as those registrations which consist of stops arranged in such a manner that the harmonic overtones of the lower stops duplicate the fundamental tones of the higher stops.
Examples: Open 8' (Principal) + open or stopped 4'
Open or stopped 8' (Principal or Quintadena) + 22/3' Quint
"Non-blending" registrations may be defined as combinations of stops arranged in such a manner that the harmonic overtones of the lower stops do not duplicate the fundamentals of the higher stops.
Examples: Stopped 8' + stopped 2' or open 2'
Stopped 8' + stopped 4' or open 4'
Blending registrations are used for music which demands the full chorus attribute of the organ. Non-blending registrations should be used where the music is to stress the maximum independence of line, such as in the typical bicinium type of chorale prelude.5
Some compositions may feasibly use either a chorus type of registration or a contrasting non-blending registration which stresses independence of line. Hence the dividing line between the two types is not clear. To express this ambiguity of intention, hybrid registrations are useful. Some of the stops blend with each other, while some do not.
Examples: Open 8' + stopped 4' + open 2'
Stopped 8' + open 4' + open 2'
In the first example, the open 8' combines with both the stopped 4' and open 2,' but the open 2' cannot combine with the stopped 4' because there is no 2' partial in the stopped 4'. In the second example, the stopped 8' can combine with the open 4', but not with the open 2'; also the open 4' and open 2' can combine with each other. For both examples, the character is not clearly either "blending" or "non-blending." Registrations with this property might be best used in music which has three or four voices where both the cohesion of the lines and their independence are to be stressed simultaneously.
These observations lead to the conclusion that successively higher pitches in a registration should be more open acoustically.
Example: Stopped 8' + partially open 4' (Koppelflute or Rohrflute) + open 2.
Single stops can also exhibit this hybrid characteristic. For example, the bottom octave may be stopped, the next octave partially stopped, and the treble fully open.
Composite Solo Registrations
The foundation 8' flutes should contain the 4,' 22/3', 2' and 13/5' partials, so that the mutation stops can join with them acoustically. The 4' flutes should contain prominent quint partials, if there is a Larigot or quint at 11/3' above. A conclusion which follows from this type of design is that the stop which determines the musical quality of a Cornet V is the 8' flute that supports it, rather than the mutations of which the Cornet itself is composed.
Solo registrations involving reed stops may be either blending or non-blending. It is interesting to contrast the combination Oboe 8' + flute 4' with the combination Clarinet 8' + flute 4'. The action of the flute in each case is different. There is, however, a little of every harmonic to be found even in the hollow-sounding reeds such as the Clarinet and the Krummhorn, because the reed itself produces a full series of partials.
If we contrast the registration Oboe 8' + quint 22/3' with Clarinet 8' + quint 22/3' we find that the adhesion of the quint to the Clarinet is stronger than the cohesion of the quint with the Oboe. This happens because the quint harmonic (22/3') is much stronger in the Clarinet than it is in the Oboe. A composite solo registration may be used with either a blending or a non-blending accompaniment registration, depending upon the character of the accompanying voices.
Conclusive Statement of Theory
This present theory of registration is easy to apply. If a stop at a lower pitch contains a harmonic that can bind with the fundamental of a stop at a higher pitch, then those two stops are capable of a good blend. If not, they will be limited in their capability of blending, or prevented from it altogether. An ensemble composed from a "non-blending" specification (such as is found in small neo-Baroque "revival" organs) comes out in layers, rather than producing a blended, cohesive, and "blooming" sound.
Specification of Foundation Stops at 8' and 16' Pitches
A practice which flows from the acoustic analysis of specification is the placement of open and partially stopped flutes at the 8' pitch in the manuals and at the 16' pitch in the pedal organ. This is much in contrast to the idea of placing them exclusively at the 4' pitch and higher in the manuals and only from the 8' pitch upward in the pedal. In the manual divisions, the economy of the organ and the space it requires are not greatly affected, since in most cases the bottom octave of open flutes at the 8' pitch is stopped and made of wood to assure quickness of speech. The provision of a narrow-scale open subbass in the pedal requires room overhead and this stop is expensive; but this expense should be more than offset by the fact that such a pedal division is more versatile and blends so much better than the alternative. The organ can be made a stop or two smaller than might otherwise be planned. The expense of the open 16' stop is more than recovered because a smaller pedal organ will actually sound better and more compelling.
When the pedal is based upon a 16' open flue, producing a relatively quiet tone--about the same intensity as a normally stopped Subbass 16'--there is an exquisite blend of harmonics. The upper partials of the soft open 16' are able to combine with the fundamental tone of the various members of the chorus above, particularly the 8' Principal.
This is the design of the pedal organ specification which is found in the Cahman organ of Löfsta Bruk.
Öppen Subbas 16'
Principal 8'
Gedackt 8'
Kvinta 51/3'
Oktava 4'
Rauschkvint II
Mixtur IV
Basun 16'
Trumpet 8'
Trumpet 4'
It is exceedingly rare. Cahman also did another interesting thing. The combination Gedackt 8' , Quintadena 8' and Quint 22/3' is repeated both in the Great and Positive organs. Are we to realize from this repetition that Cahman provided the Quintadena 8' in each case to secure an acoustical, harmonic "locking in" with the quint 22/3' above it? Most modern specifications would have omitted the Quintadena, probably on both manuals, and supplied a stopped 16' to the pedal, substituting for the Open Subbass 16' a louder Principal 16'. The particular quality which sets this Cahman organ apart as a gem among artistic instruments would be destroyed.
The Open Subbass of the Löfsta Bruk organ is made of wood and has a fairly narrow scale. In the published photographs of the organ, the end of the largest pipe can be seen behind the 8' Prestant of the pedal organ. The lowest pipe is approximately seven inches square. If this principle of specification and voicing is to be retained in an organ large enough to offer both an open and stopped 16' flue in the pedal, it is important that the open stop be of narrow scale and voiced quietly so as to support the chorus above. When 16' open flues are scaled and voiced loudly, so as to "add power", their harmonic development is much reduced and their ability to contribute to a unified chorus ensemble is lost. Therefore the 16' open flue stop should be planned to be no louder than any stopped 16' open flue which may accompany it in the pedal.
An Example of the 16' Open as the Only Pedal Foundation Stop in a Modern Organ
The Casavant organ at the Dordt College chapel at Sioux Center, IA, was built under the supervision of the late Gerhard Brunzema. It is a 37-stop instrument which contains only principals and reeds in the pedal according to this disposition.6
Praestant 16'
Octaaf 8'
Octaaf 4'
Mixtuur VI
Bazuin 32'
Bazuin 16'
Trompet 8'
Cornet 2'
Since there is only one 16' flue stop, this stop also has to be able to fulfill the role normally taken by a stopped 16'. Therefore it must not be loud. But if the 16' foundation cannot be loud, how is power to be built up? The Sioux Center organ relies on its reeds rather than its flue stops for power in the pedal organ. This also happens in the Löfsta Bruk organ.
The Use of Mutation Stops to Support a Pedal 16' Flue Stop
The Löfsta Bruk organ builds power for its 16' flue both through its reeds and through a 51/3' pedal quint. This method of building power and clarity without overvoicing the 16' flue stop was followed regularly by the late Nils Hammarberg, a modern Swedish organbuilder of Göteborg. A stopped 8' pipe acquires definition though the reinforcement of its third partial, the 22/3' Quint. The Quint's fundamental is the same as the third partial. Cahman specified a Quint 51/3' in the pedal organ to complete the same harmonic function that the 22/3' Quint fulfills in the manual divisions. The combination of a soft open 16' together with a quint supporting its third partial gives the pedal organ a firmer foundation than any loud, wide-scaled diapason could ever provide.
The mutation stop must be narrowly scaled and gently voiced, and a true principal rather than a flute. This is also a prominent characteristic of the 22/3' and 2' stops in the Great organ of the nineteenth-century Brisbane instrument in Australia. Blending tone is aided by conservative scaling and gentle voicing, both of the fundamental tone and its corroborating harmonic.
Hammarberg continued this tradition with the provision of a pedal stop called "Aliqvot," a name which simply means "harmonics." It can refer to any useful combination of supporting harmonic partials. In his most recent work it consisted of the following 16' partials:
51/3' quint = third partial
31/5' tierce = fifth partial
22/3' quint = sixth partial
2' fifteenth = eighth partial
Hammarberg developed this idea because in Sweden, organs are placed in the gallery at the western end of the church and there is no headroom for open 16' pipes. It substitutes for the open 16' sound a resultant:
Alikvot 51/3' C 96 Hz
Principal 8' C 64 Hz
difference 32 Hz = 16' C
He also provided the 32' resultant in the same way:
Kvinta 102/3' C 48 Hz
Principal 16' C 32 Hz
difference 16 Hz = 32' C
Sometimes the Alikvot mixture has less than four ranks and sometimes more; Hammarberg sometimes built it in the following way:
51/3' quint = third partial sounding G
31/5' tierce = fifth partial E
22/7' flat seventh = seventh partial flat A#
17/9' ninth = ninth partial D
A typical specification for such a pedal organ is:
1. Subbas (wood, stopped) 16'
2. Kvinta 102/3'
3. Principalbas 8'
4. Gedacktbas 8'
5. Alikvot 51/3' + 31/5' + 22/3' + 2'
6. Bombard 16'
7. Trumpet 8'
8. Rörskalmeja 4'
9. Koralbas 4'
Hammarberg built this plan in conditions where headroom was restricted, from about 1981, and used the Alikvot mixture as well as the 102/3' plus 16' resultant in various instruments dating from the 1960s and 1970s. Examples of this work may be found in Mora, Boras, Göteborg, Falkenberg and Grebbestad, all in Sweden. In all of these organs, the presence of the Alikvot stop relieves the 16' from any obligation to attempt to produce power through volume, with the attendant deterioration of its tone.
Hammarberg's plan of pedal specification works well with gently voiced open 16' flue pipes, to develop a pedal organ of considerable power, while allowing the open 16' flue to remain as the only 16' flue stop in the division. Hammarberg's ideas combine well with Brunzema's plan (above) to give the following:
1. Subbass 16' wood, open narrow scale, about 7≤ CCC as at Löfsta Bruk
2. Quint 102/3'
3. Principal 8'
4. Gedacktbass 8'
5. Quint 51/3'
6. Coralbass 4'
7. Alikvot, composition as appropriate
8. Basun 16'
9. Trumpet 8'
10. Rohrshalmey 4'
Summary
The modern organ reform movement has given strong support to the exclusive use of gedackts and other stopped pipes at 16' and 8' pitch in small organs. This type of specification is derived from a "Neo-Baroque" Germanic tradition of organ building. Although these stopped pipes sometimes have narrow chimneys as in the Rohrflute, they nevertheless act as stopped pipes in the ensemble. This practice of specification leads to a form of non-blending registrations.
It is curious that the Italian organ, in which one always finds open pipes for foundation tone, is hardly built today, while the typical "reform movement" type of instrument, with a high percentage of stopped pipes, is commonly built. This is not merely a result of economic considerations, but rather a question of style and fashion.
Derived from this background is the practice of specifying a stopped Subbass as the pedal foundation stop. It provides the fundamental pitch in an undefined sound that blends with difficulty; and when pushed to provide greater volume, its tone deteriorates very quickly. A stopped Subbass has little blending power because it has no harmonic at the octave. This defeats the purpose for which it is intended. A 16' pedal stop should do more than supply a fundamental pitch; it should provide a harmonic series to support the chorus above.
We have examined pedal organ designs by builders who have not frozen their thinking into traditionally accepted ideas. The contemporary organs of Brunzema and Hammarberg take much of their design from the organ reform ideals, but also demonstrate innovative ideas which reinforce the true acoustical nature of the instrument. Let us turn to models such as these, rather than the typical "organ reform" prototypes, in order to construct organs of moderate size that do not lose our public for want of a good foundation for singing.
If we emphasize gently voiced open pipes as the natural source of fundamental tone, and obtain the power of the organ by means of harmonic reinforcement, we will assure that its sound has that live-giving warmth which will appeal to the musical public.8
Appendix
The Löfsta Bruk Organ
by John Hamilton7
The sumptuous Löfsta Bruk organ was built in 1728 by Johan Niclas Cahman, a North German builder who had emigrated to Sweden. Of twenty-eight registers (two manuals, pedal), it was conservatively conceived; it is today Scandinavia's finest example of the sort of instrument known to the Praetorius/Scheidemann/Scheidt/Buxtehude school. The lavishness of conception is indicated in, for instance, the pedal's two full-compass full-length sixteen-foot registers, a Principal and a Posaune--in a church seating barely three hundred. The organ has largely escaped the periodic "modernizations" which have plagued many important old instruments. When nineteenth-century tastes called for a different sort of churchly music-making, the Ryggpositiv windchest and pipes were carefully removed and stored in the church's attic; Romantic tastes were satisfied by the two-manual-and-pedal reed organ which replaced the Ryggpositiv. A restoration in the early 1960s, by a Danish firm, was in the tradition of the best obtaining taste of that decade; it was well carried out but, alas, today's wind-supply is the mercilessly steady nineteenth-century norm, today's temperament is nineteenth-century equal, today's reed tongues are modern (the restorer discarded the old tongues without making measurements or metal analysis), and today's key action possibly is overly spring-loaded. Plans are afoot to correct these modern intrusions.
Tone is big, noble, unforced, in the north European historic tradition. Plenums admirably support the ardent congregational singing known to have characterized the eighteenth century: today's listener readily envisions vigorous hymn singing from strong-lunged Walloon ironwrights, who sat together in the church's most prestigious area. Of particular interest are the organ's mixtures, all of which contain third-sounding pipes contributing strength and color to the plenums. Individual Principal registers are among the most gloriously singing known to this listener.
Today's organists at Löfsta Bruk are Birgitta Olsson, the excellent parish organist, and Göran Blomberg of Uppsala University, who with a background in musicology, organ performance, and classical archaeology, is a strong summer presence. Blomberg's personal involvement with the instrument coincides with the period of its modern international reputation starting around 1980; his tireless, knowledgeable commitment to its becoming known have resulted in the organ's having become widely recognized even earlier than was the village itself. He has recorded an excellent selection of material by Buxtehude and Bach on an LP released by Bluebell-of-Sweden and is preparing digital recordings. Birgitta Olsson and Blomberg have organized a succession of summer "Cahman Days" forming an annual framework for presentation of the instrument; these included an international festival in August 1987, during the Buxtehude anniversary. And Blomberg offers numerous demonstration recitals on the instrument for groups of both lay and professional visitors.
