“Making Itself Heard: The Many Voices of the Organ” (part I)
Among other things, Christmas is a time of year when organists are traditionally in high demand. This is mostly because the organ has long been the main instrument for Christian music, and Christmas is one of Christianity’s most significant holy days. At Christmas time, people have come to expect powerful music from the organ, music of grandeur and joy, as well as lullabies and cradle songs. But still, nothing is more impressive than the sound of full organ washing over our ears. Of course, the organ is especially well-suited to this task because of its capacious wind supply and many stops, yet the organ alone cannot create such an amazing experience. Its acoustic environment, the room in which an organ stands, also contributes greatly to the beauty and volume of the instrument. In large buildings, such as cathedrals and concert halls, however, creating such a grand and powerful sound has proved seriously challenging because the volume of space to be filled can be so enormous.
Today, organ students are used to finding small pipe organs in conservatory and school practice rooms, and some professional organists even keep such instruments at home for private practice. Over the past few centuries, there have also been numerous chamber organs built for homes or small concert halls. But by far, the majority of organs have been built for giant spaces, from cathedrals to convention centers. Besides the various purposes of such organs — accompanying singers, performing solo pieces, playing with orchestras — builders have also thought how best to design instruments that are both flexible and yet capable of filling large spaces with sound. This has proved a difficult problem, which has been solved in many different and ingenious ways. Indeed, the various organ designs found throughout different countries demonstrate the many methods builders have used to meet this challenge. While we cannot look at every detail of how different schools of organ building have answered this question, we can at least take a brief tour of organs throughout Europe to examine some of the solutions that builders there have tried throughout history.
Before setting off on our journey though, we need to spend a little time looking at the large rooms where organs live. The oldest churches were made from huge boulders or slabs of stone. This kind of thick stonework prevented even the longest bass sound waves from easily escaping a room, and many of those rooms were hundreds of meters long with ceilings high above the ground. Such generous dimensions allowed sound to roll around a room, echoing off walls, ceilings and floors. The size and qualities of these acoustic spaces magnified the natural volume of the organ, allowing sounds to hang in the air for several seconds after the organist finished playing. So upon releasing the final chord of a piece, the organ’s voice could be heard traveling throughout the length of a room, echoing away into
the distance. In some of the largest European churches, for example, this reverberation can last up to 8 seconds or more. Generally, acousticians (sound engineers) working with organ builders consider a reverberation time of at least 3 seconds to be ‘lively’, rather than ‘dry’, as is true in rooms with barely any reverberation at all.
Beginning from the 18th century, organ builders also faced the problems of building organs in concert halls. These buildings presented builders with a different set of challenges than reverberant churches, yet builders still borrowed the majority of their designs from church instruments. Because concert halls were intended as performance spaces for large groups of instruments, such as orchestras, the amount of reverberation was usually somewhat less than in large churches. Also, organs built for such rooms needed the ability both to collaborate and compete with large orchestras. Because this required a large range of sounds and dynamics, these instruments grew to be remarkably large, often nearing or even surpassing 100 stops!
So, how have organ builders met the demands of all these different acoustical spaces? In the most general terms, they have only had two options: change the wind or change the pipes. Though it seems natural that the easiest way to make an organ louder is to increase its wind pressure, this approach was not widely accepted until the later 18th century, partly because of the difficulties it created for voicing pipes. The second solution, on the other hand — changing the pipes — offered several options, from increasing the shape and number of pipes to changing the way they are voiced and tuned. Still, we have to remember that the larger the organ, the more expensive it can be, so the number of pipes is often limited by the money that is available.
One final point must be repeated before setting off on our journey. We cannot take time on this trip to visit every innovation that enabled the organ to fill vast rooms, so we must be happy with simply looking at a few examples and methods. The earliest examples of fully developed organ building, at least in the modern sense of an instrument with multiple keyboards and stops, appear to have originated from the Low Countries, what we today call Holland and parts of northern Belgium. So, let’s begin there and look at the Dutch solution to the problem of filling large churches with sound.
Traveling to the Low Countries, we discover that builders there had a practice of doubling the treble registers of pipe ranks, particularly principals (sometimes called Praestants). What does this mean? For some rows of pipes, there were two unison pipes speaking for
each note or key that was played, starting from the middle of the keyboard. The use of two pipes helped strengthen the treble range of a stop by giving it a somewhat louder and larger sound. This was useful not only for reinforcing the higher notes of the keyboard, where the quality and strength of the sound started to fall off as the organist played higher and higher notes, but also for making the soprano voice (which was often the melody) clearer and easier to hear in a large room. By the 18th century, the practice of doubling trebles was considered a necessary means of leading large groups of people when singing. We can still hear their effect today by listening to people singing along with those organs.
Sometimes in Dutch organs, it is easy for us to see which ranks are doubled by simply looking at the façade. We can see where lower flats of pipes may be turned upside down so their feet point up toward the downward-facing feet of the pipes in the higher flats. When we look at these pipes, we feel as if the pipe flats are reflections of each other, or mirror images. But even if we cannot see inverted pipes in the façade, it is still possible for us to hear which ranks are doubled by listening carefully to the speech and tuning of different treble registers. Since it is notoriously difficult to keep doubled ranks in tune, we only need to listen for pipes that are either out of tune, or for sounds that seem to come from a single pipe but that speak from two different sources at slightly different times. (To be continued)