Most organs have two or more manuals, and organ composers have, for most of the time that organ music has been written, been able to assume that an organ would have at least two manuals, so they have sometimes written music that expressly requires two manuals. There is also music that can only be played appropriately on one manual, that is, with both hands on the same keyboard as each other at any given time. And of course there are pieces or passages that can be distributed over manual keyboards in a number of different possible ways. These can vary with the instrument or with the artistic preferences of the player. How can you, the student, learn how to tell what the best way is to deploy your hands on the various keyboards of the organ that you are playing, and then how can you learn to do so comfortably?
There are two essentially different ways in which an organ piece can utilize two manuals: the two hands can be on separate manuals—each on its own keyboard—at the same time, or both hands can move, more or less together, from one manual to another in the course of a piece or a passage. (Of course these can be combined or found together in one piece, as, for example, when both hands move from one manual to two different manuals, or the hands start out together and one of them moves to a different keyboard at some point.) Sometimes these arrangements are specified by the composer. Other times they are optional possibilities at the discretion of the performer.
It makes sense for the two hands to be on different keyboards at the same time if:
1) The notes in the two hands overlap a lot, so that it is either actually impossible to make all of the notes of all of the voices (or all of the parts of the texture) sound if they are played together on one keyboard or impossible to make different voices clear because they are so jumbled together.
2) The composer (or player) wants the musical content of the two hands to sound different for compositional or artistic reasons.
The first of these is the situation in the Bach chorale Herr Gott, nun schleuss den Himmel auf (reproduced in the April 2014 installment of this column), and also in much of the writing in the Bach trio sonatas. It occurs throughout the organ repertoire, in music from all eras. Here are a few examples:
Buxtehude, Nun freut euch, lieben Christen g’mein, excerpt (Example 1)
Bach, Trio Sonata No. 1 in E-flat, first movement, excerpt (Example 2)
Saint-Saëns, Improvisation, op. 150, no. 1, excerpt (Example 3)
In these examples, each staff represents one hand and one different manual. In each case, something in the note-picture would be misrepresented if the hands were not placed on different manuals. In the Buxtehude, there are no specific individual notes that would be lost if the player were to try to play the passage on one manual, but throughout these measures the direction of the counterpoint would become unintelligible. In the Bach there are places where the voices actually coincide on notes, and also places where the voices cross in a way that would obscure the counterpoint if the two lines were on the same keyboard. In the Saint-Saëns, the left hand lines largely duplicate the notes of chords that are being held in the right hand. This texture would be literally impossible if the two hands were on one keyboard: either some notes in the left hand line would have to be left out, or the long chords in the right hand would have to be released. (This writing is probably intended as a re-creation on the organ of something that would be quite natural to the piano, through the use of the damper pedal.)
In each of these cases it would be evident from looking at the music that the two hands had to be on different keyboards, whether the composer has said so or not. It should be noted that in many keyboard pieces there is just an occasional note that is shared by two voices or by two elements of the texture or by the two hands. A small amount of this overlapping, crossing, or sharing does not constitute a reason to decide that it is necessary to separate the hands onto two keyboards—though it might or might not be a good idea for other reasons. A large amount of this potential confusion probably does.
The optional or purely interpretive/artistic division of the hands between two manuals is sometimes indicated by the composer, as in, for example, the Orgelbüchlein chorales Der Tag der ist so freudenreich and Das alte Jahr vergangen ist. Here the ornamented chorale melodies in the right hand do not bump into the alto and tenor voices in the left hand except fleetingly. It would not occur to a performer that these pieces had to be divided onto two keyboards. However the composer has expressly labeled them “for two keyboards.” If he had not, a performer might very well have decided to arrange the hands on two keyboards in any case, but not out of necessity. In the Orgelbüchlein chorale Christe du Lamm Gottes there are four voices in the hands (and one in the pedals). It is entirely possible to play the piece with the hands on one keyboard: nothing of the note picture is lost. However again the composer has marked the piece for two manuals and pedal. This is an optional coloristic choice, again one that, in the absence of any instructions from the composer, a player might or might not have made.
In Example 4, an excerpt from Saint-Saëns’ Improvisation, op. 150, no. 2, the two lines do not bump into one another at all. (This excerpt is the whole of the passage.) The composer has directed that they be played on different manuals only and specifically to create a contrast of sound colors.
So how can you decide, in the absence of any indications from a composer, when to consider dividing your hands between two manuals?
It is usually inappropriate or actually wrong to place the two hands on two separate manuals if the passage that you are playing contains musical lines that migrate from one hand to the other. It is at least potentially all right to do so if each hand plays self-contained musical material. For example, it is quite feasible to play the entire soprano and alto voices of the Orgelbüchlein chorale Wer nur den lieben Gott läßt walten in the right hand, leaving the left hand free to play just the tenor line. It is then a valid possible choice to play the tenor line on a separate manual (as, of course, an optional choice by the player, since it is not something that the composer has mandated). Likewise it is possible to play both the alto voice and the tenor voice of the chorale Alle Menschen müssen sterben in the left hand. This would enable the right hand to play the soprano voice —the chorale melody—on a different manual.
However, in the chorales In dich hab’ich gehoffet, Herr and Erstanden ist der heil’ge Christ, the alto voice has no choice but to pass back and forth between the two hands. Therefore it would not work to have those hands playing different sounds. That would cause the sound of the alto voice to change at random times. This situation is often found in fugues. For example, in Example 5, from the Fugue in C Major, BWV 545 by Bach, the alto voice has to be in the left hand in the first quoted measure, and has to be in the right hand in the following measure and again in the last measure of this line. If the two hands are not playing the same sound on the same manual, then this will create a random and odd-sounding change of tone color.
In general, if you are thinking of dividing the hands between two manuals in a way that has not been expressly indicated by the composer, you should satisfy yourself that it makes musical sense to do so. If you are dividing the hands between two keyboards in a way that has been indicated by the composer, try to be sure that you understand why the composer set the music up that way.
When an organ piece moves from one manual to another in the course of a movement or a passage, it does so in order to bring about a change of sound. Very broadly speaking these changes of sound are of two sorts: changes that are for the sake of change—variety as such or different sounds to fit the character of different sorts of writing; and sounds that are part of a dynamic scheme—a crescendo or diminuendo, or a dynamic contrast. Of course these two blend into one another. Any change in volume tends also to be a change in character, and any change in character tends to include at least a small change in volume.
Choices about changing manuals during a piece are sometimes specified by a composer and sometimes left to the judgment of the player. In general, earlier composers specified less than later composers. Some of the ways in which a composer might address issues of manual changes are:
1) Not at all, that is, no indications about manuals in the music, and no registration indications that might imply anything about manual changes. This is the situation with most, but by no means all, organ music from before about 1700.
2) With indications of dynamics. In Example 6, from the chorale Nun lasst uns Gott dem Herren by Vincent Lübeck, dynamic markings are used to indicate an echo effect that the composer would have achieved by a manual change.
(Note that dynamic markings can also refer to changes of registration independent of manual changes, and to the use of swell pedal or some form of crescendo pedal.)
3) With specific indications about keyboards. See Example 7, from the chorale Nun lob mein Seel’ den Herren by Buxtehude, in which he specifies Rückpositiv and Oberwerk. (This also creates an echo effect, and it is kept up throughout this work.)
Mendelssohn and Reger, among many others, tend to use roman numerals to specify a difference in manuals.
In Example 8, the opening of the Choral in E Major by César Franck, the composer indicates manual changes by names of specific keyboards.
This is found throughout organ repertoire from the mid-nineteenth century on. Often indications for manual changes are accompanied by specific registrations—initial registrations for each keyboard and perhaps changes along the way.
Next month’s column will continue exactly from here, addressing the question of how to think about manual changes in the absence of any instructions from a composer, and then moving on to techniques and specific exercises for making the physical act of changing manuals comfortable and reliable.