First Presbyterian Church
Las Cruces, NM

A Brief History of Organs and Organ Music

Howard A. Smolleck

The musical instrument that we designate by the name A organ@ has, even more so than most musical instruments, a long and varied history. Before considering some of the historical highlights and their consequences, let us examine some of the devices that today bear the name A organ@ . We will see that some of these devices are not really A organs@ in a true historical sense, although they may be used in that function.

Electric organ is the name given to a musical instrument that uses an electrically-driven blower to supply air to reeds. Such a device is in reality a reed organ. Non-electric predecessors of this device, often having many sets of reeds with air supplied by a bellows or other means, have been used for more than a century in houses of worship and entertainment. Some very good quality instruments were made. A more familiar version, widely purchased for homes a century ago, required the player to pump a set of bellows alternately with the feet.

Electronically-amplified reed organs were produced in the mid twentieth century for use in churches and homes. These are in reality not A electronic@ organs (which see below), because the sound is produced by vibrating reeds and not by purely electronic means.

Smaller versions of the electric organ are still available. In most cases, these have a reduced piano-type keyboard with miniature-sized keys for the right hand and an accordion-like set of buttons for the left hand. The buttons produce either chords (operating groups of reeds through a mechanical selector linkage) or bass tones. Most of these instruments are inexpensive and not constructed for long life or quality sound; many are toys. However, a few companies have made notable exceptions of good quality. These instruments are properly called chord organs.

Electronic organs are instruments that use electronic circuits to produce signals that are amplified and sent to loudspeakers or headphones. Until the 1970's, most of these devices used oscillator circuits (employing vacuum tubes or transistors) to produce tones; the tones were then mixed by electric switches associated with keyboards. Some of these switching mechanisms were very mechanically complicated.

An electronic oscillator requires some kind of nonlinear amplifying device such as a transistor or vacuum tube. Early examples (1920's and > 30's) used vacuum tubes, and some of these were built even in the 1950's and > 60's. The invention of the transistor around 1948 brought in the era of solid-state electronics. Such circuits could operate at considerably lower voltage levels than vacuum tubes, with far less heat generation. Transistor devices, as we recall from transistor radios compared with the old vacuum-tube models, are far more rugged and are well adapted to battery use. Many transistor electronic organs are still providing faithful service.

Oscillator organs are beset by some problems, such as the need for frequent tuning and the problem of keying the oscillators in such a way as to avoid sounds such as A pops@ when the key is depressed. In some cases, the oscillators run continuously and the key simply switches the appropriate signal to the amplifier. In other instruments, the oscillators are turned on as required by depressing the keys. Pros and cons were hotly debated for each of these methodologies.

One ingenious application has been the multivibrator circuit, which can generate sounds whose frequencies are integer multiples. Thus a single multivibrator oscillator can produce all the C= s, another is tuned to generate the C-sharps, etc. In such an instrument, instead of having 500 or so tuning points (as in my large home instrument), only 12 oscillators need to be tuned. The problems of A component drift@ still remain, though, making the instrument go out of tune as time passes.

One particular make of electrical instrument has been widely known for perhaps 70 years, even to the extent of having much organ music marked expressly for it. This is the Hammond organ, which uses rotating toothed wheels passing in front of magnetic pickups, rather than oscillator circuits, to produce the basic tones. Since the speed at which an alternating-current synchronous motor operates depends upon the frequency of the power provided by the utility, and since that frequency is usually held constant to within a small fraction of a percent, these instruments never need tuning. Multiples of the frequencies are combined by the player using sliders or dials with different volume levels per harmonic. Despite the extensive publicity formerly given to these devices, and their advantage of requiring no tuning, these instruments do not represent true organ sounds well.

All of these electronic instruments, regardless of the multitude of improvements made over the course of eighty years or so, are limited by the lack of ability to reproduce attack and release sounds and other nuances made by blown instruments such as the flute, trumpet, or organ pipe. Since the 1970's, advances in digital electronics have produced the digital electronic organ in an attempt to surmount some of these obstacles.

In its simplest form, a digital organ might include the tiny circuit, programmed into a microchip, that plays A Happy Birthday@ when a greeting card is opened. At the other end of the spectrum, large church and concert instruments have been developed that use the equivalent of several Pentium-class processors operating simultaneously to produce very sophisticated waveshapes. Between these extremes are the Casio, Yamaha, and other makes of A electronic keyboard@ of widely varying price, quality, and acoustical fidelity.

With these instruments, actual wind-blown sounds can be digitally sampled and the resulting sound can be scaled for all tones on a keyboard. Attacks, releases, and even random A air sounds@ can be generated. The accuracy of the circuit to reproduce the original sound is limited by the number of samples per second (usually in the multiples of thousands). Faster, modern computers allow considerably better sampling. This field is still developing, and the modern instruments are far more convincing than the early digital organs of the 1980's.

We should always recall that, regardless of how faithfully the device electronically reproduces the waveshapes of the original type of instrument that it seeks to imitate, the effect is limited by the quality of the amplifier and speakers. Furthermore, the emergence of all sound from a single speaker location can never truly imitate the distributed acoustical sources present in real pipes or, for example, orchestra players.

Having discussed these devices, we move to what in many people= s minds is the only A true@ organ: the pipe organ. In a pipe organ, musical tones are produced by air rushing through pipes (some of which may actually contain reeds). Because an organ uses air (called A wind@ ) under a small pressure, its sound-production mechanism is similar to that of mouth-blown instruments or to the human voice.

Although all pipe organs produce tones by means of air movement, the manner of controlling the wind to each pipe is drastically different in different types of instrument. The earliest full-scale organs were, of course, mechanical or A tracker@ instruments. In these instruments, pressing a key sets into play a series of purely mechanical motions through an often-complicated mechanism (sometimes called the A action@ or A harness@ ) that eventually causes the valve under a pipe to open in order to admit air. These instruments reached their apex of development from perhaps the seventeenth to the nineteenth centuries. The eighteenth century, in particular, was notable for the use of large mechanical instruments of high acoustic quality.

Even after the introduction of improvements in organ mechanical action as noted below, the tracker action has remained in favor with some organists and has even seen a great resurgence in the late twentieth century because, as one English builder phrased it, it creates A a more intimate relation between the performer and the pipes@ . Many mechanical instruments have in fact used some improvements in organ control; for example, the instrument at First Presbyterian, although a mechanical action, uses electronic combination action and electric solenoids to move the sliders in the wind chest for stop selection.

Mechanical instruments are sometimes advertised to be simple and long-lasting compared with other organs. Examples of fine historic instruments built several centuries ago and still in regular use are cited to substantiate this. This statement must be qualified. Mechanical instruments contain complex mechanical linkages that are subject to the ravages of dust, moisture, dryness, mechanical vibration, component fatigue, etc. As with any complex mechanical system, proper maintenance is essential. This includes regular cleaning, tuning, tightening of mechanical parts, compensating adjustment of mechanical linkages, and even periodic replacement of more transitory parts such as leather and felt. In order to keep an instrument in top condition, this maintenance responsibility must be assumed. It is cost-intensive because it is labor-intensive and requires skilled, trained persons. However, mechanical instruments (in contrast with electronic devices) operate on straightforward mechanical principles that can be understood without recourse to A modern@ technology, and can thus be understood and repaired by employing a series of straightforward, simple procedures.

Mechanical instruments, especially large ones, have been beset historically by the problem of increasing clumsiness of key action as the mechanical harness is called upon to actuate more and more ranks of pipes. Furthermore, the effectiveness of mechanical action limits the distance between console and pipe. For this reason, various means have been explored for making the key action lighter while controlling more pipes at greater distances from the console. Beginning in the 1840's, A pneumatic assist@ devices using organ wind were developed. These function much like the power-assisted brakes on a modern automobile, in which a small touch on the pedal will allow engine vacuum in a cylinder to exert far more force than required of the foot. In organs, some of these early devices used a vacuum, but most simply employed organ A wind@ ; i.e., air under a small positive pressure. Long after electrical assist was developed in the mid nineteenth century, some prominent builders (such as Cavaille-Coll in France) preferred the pneumatic-assist devices, as they were safe, reliable, and easy to understand. Like other bellows-type devices, however, the leather would require replacement after several decades, necessitating a time- and skill-intensive rebuild.

Such developments led in the 1860's to the tubular-pneumatic instrument, in which air movement in small tubes (often flexible lead/tin tubes of inside diameter about the diameter of a pencil) formed part of the signal-transfer mechanism between key and pipe. Since air is highly compressible and thus yields a finite maximum speed of transfer, however, and because of the added complication at both ends of the tubes, these efforts were not considered wholly satisfactory. The judgment on them was, as in most cases of radical organ modification, highly polarized. For example, one famous mid-nineteenth-century British organist heralded the tubular-pneumatic development as one of the greatest inventions applied to the organ; a contemporary colleague of his claimed that it was one of the worst ideas imaginable.

The increasing availability and use of electricity in the nineteenth century led, of course, to its consideration for organ use. The ultimate development was the electropneumatic organ, in which the air valves under the pipes are opened by the assistance of an electric current controlled from the keys. Early experiments in this regard were conducted in the 1850's, even before the advent of the tubular-pneumatic action, but the major share of development in this direction came half a century or more later. Early efforts required higher voltages and currents to open the valves, causing the key contacts to arc and burn and depleting the batteries which, before generators, were the only available source of direct current. Considerable reduction in current and voltage were realized by about 1900, and the use of small generators became widespread. Modern electropneumatic keyboards and other mechanisms are very reliable, and the generator has been replaced by a solid-state rectifier.

Electropneumatic action opened some significant possibilities. No longer was the distance between keys and pipes limited to a few tens of feet. Organ divisions were installed at widely-separated parts of large buildings, not always with acoustically satisfactory results. Furthermore, huge numbers of pipes could be activated from a keyboard with no change in touch compared with playing a single rank. In addition consoles could be mobile and the same ranks of pipes could be played by consoles in different locations. Some of the most recent developments in electropneumatic action include the digitizing of signals at the console, which are transmitted to the pipe vault by a single coaxial cable or even by radio. This allows the intriguing possibility of recording the digital signals produced during a performance and then A playing@ these signals back into the instrument in order to hear a truly exact repeat of the performance, reminiscent of player-piano-type efforts applied with varying success to the organ during the past century. A further possibility, discussed and perhaps implemented in France (where large, old organs of quality abound), involves digitizing some of these old instruments and playing organs in several cathedrals simultaneously, by phone line, from a single remote location.

Other developments paralleled the emphasis of electropneumatic action during the previous century, including developments in organ tone, placement of pipes, inclusion of percussion sounds, etc. The nineteenth and early twentieth centuries witnessed a tremendous proliferation of imitative sounds, partly due to the theater-organ phenomenon. For better or worse, the theater organ exerted a significant effect on the perception of organ music by thousands of persons. Some historians have expressed the belief that more people were exposed to organ music in the US and Britain during the first half of the twentieth century through the theater organ than by means of the church organ.

Experiments with higher air pressures led to new designs in the early twentieth century. Powerful ranks of pipes operating under as much as 100 inches of wind (roughly 50 times what most church organ pipes require!) were developed. Several of the largest organs ever made include the electropneumatic instrument in the Atlantic City Auditorium (7 manuals) and in the Wanamaker store in Philadelphia. Significantly, these instruments were built in the 1930's, in the waning heyday of the theater organ. Some of these instruments played golckenspiels, marimbas, drums, and even grand pianos. We tend to think of percussion sounds as something originating with theater organs of the early twentieth century, but unusual sounds (such as warbling birds) were popular on church organs of three hundred years ago.

The mid twentieth century has witnessed a return to A classical@ organ principles, including more A traditional@ voices, lower wind pressures, more exposed ranks of pipes, and fewer non-organ-like sounds. Of course, this classical revival re-stimulated interest in mechanical instruments. Both mechanical and electropneumatic instruments of quality are being built today. Each has advantages and disadvantages. Although electronic instruments (especially digital) have encroached on this field, quality pipe organs (some very large) are still being built. Organ playing and organ construction are still very much alive!


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Last update 2002-06-24 12:44:10