Casavant Frères Opus 3530 (1982)
31 stops/ 41 ranks/ 2056 pipes


1. Bourdon (wood) 16' 56 pipes
2. Principal 8' 56 pipes
3. Harmonic Flute 8' 56 pipes
4. Chimney Flute 8' 56 pipes
5. Octave 4' 56 pipes
6. Conical Flute 4' 56 pipes
7. Quint 2-2/3' 56 pipes
8. Super Octave 2' 56 pipes
9. Mixture (V) 1-1/3' 280 pipes
10. Trumpet 8' 56 pipes
11. Cremona 8' 56 pipes
Total pipes: 840


12. Bourdon 8' 56 pipes
13. Spitzgamba 8' 56 pipes
14. Céleste (TC) 8' 44 pipes
15. Principal 4' 56 pipes
16. Chimney Flute 4' 56 pipes
17. Blockflute 2' 56 pipes
18. Sesquialtera (II) 112 pipes
19. Mixture (V) 1' 280 pipes
20. Bassoon 16' 56 pipes
21. Trompette 8' 56 pipes
22. Oboe 8' 56 pipes
Total pipes: 884


23. Contrabass (wood) 16' 30 pipes
24. Subbass (wood) 16' 30 pipes
25. Octave Bass 8' 30 pipes
26. Bourdon (Extension of No. 24) 8' 12 pipes
27. Choral Bass 4' 30 pipes
28. Mixture (IV) 2-2/3' 120 pipes
29. Trombone 16' 30 pipes
30. Trumpet (Extension of No. 29) 8' 12 pipes
31. Shawm 4' 30 pipes
Total pipes: 332


  • Great to Pedal
  • Swell to Pedal
  • Swell to Great

Adjustable Pistons

  • General: 5 toe and thumb
  • Divisional
    • Swell - 5 thumb
    • Great - 5 thumb
    • Pedal - 5 thumb
  • Cancel

Reversible Pistons

  • Great to Pedal - toe and thumb
  • Swell to Pedal - toe and thumb
  • Full Organ - toe and thumb

Balanced Pedals

  • Swell Expression
  • Crescendo Pedal

Indicator Lights

  • Crecendo
  • Full Organ on


  • Manuals: 56 notes (CC-g)
  • Pedal: 30 notes (CCC-f)


Stop and key action is electro-pneumatic, with stop-channel chests

St. John's Cathedral Sanctuary Organ

A short (and incomplete) treatise on the pipe organ - John Botari, October 2001

Part One - The Basics

When I was asked, some months ago, to write this series of introductory articles concerning the pipe organ for a church newsletter, I had to do some hard thinking about the task. I am not, in fact, an organist, nor am I an organ-builder or an organ technician. However, I do hope that I can give a few insights into the instrument and how it can be used to make music - from the standpoint of an interested lay person!

Having told you what I am not, I will allow that I am a technologist. As such, I have always been at least somewhat interested in the pipe organ, since it occupies a fairly significant spot in the history of technology - after all, until the advent of the automatic dial telephone exchange in the early years of the 1900s, organs were, without a doubt, the most complicated mechanical systems ever attempted by humans. Fairly complex multiple-rank organs have been around since before the turn of the last millennium, and very elaborate examples date back as far as the seventeenth century. Even a small instrument comprises hundreds of pipes and all of the equipment needed to operate them. Amid all this complexity, the actions of the organist must somehow be transmitted from his or her fingers and feet to the actual sound-producing devices with sufficient accuracy and delicacy to convey a sense of artistry. This requires a lot more subtlety than the mere openings and closings of valves in some steamfitter's nightmare!

A good way of looking at this topic is to consider the instrument that's currently installed at St. John's Cathedral. It was constructed (as some may already know) in 1982 by the firm of Casavant Frères of St-Hyacinthe, Québec - certainly Canada's oldest (but by no means its only) organ-builder. It is their Opus 3530 (meaning that it was the 3530th organ constructed by them since the founding of their firm in 1879).

Like almost all pipe organs, Casavant Op. 3530 wasn't ordered from a catalogue. It was designed (by tonal architect Lawrence Ritchey) specifically for the space which it currently occupies, and with due consideration for the kinds of music that it would likely be called upon to perform. I can therefore say with a great deal of confidence that it is different (at least in some details) from any of the 3529 instruments that preceded it out of the doors of the Casavant shops.

Being a pipe organ (as opposed to an electronic one!), Op. 3530 fits nicely into the somewhat derisive description put forward by John Knox, the 16th-century Scottish reformer: because his austere piety objected to the introduction of such machinery into houses of worship, he apparently referred to the organ as a "kist o' whistles" (a "box of whistles"). If you look up into the pipe chamber (on the right-hand side of the chancel as viewed from the nave), you will see a large number of whistles (or pipes) of varying sizes - their lengths are anything from only an inch or so up to sixteen feet in this instrument. These are arranged atop boxes (called "wind-chests") in groupings called "ranks" - with each rank being a complete set of pipes producing a certain specific tone-colour. Of course, short pipes produce high notes, and long pipes produce low ones, but the actual character of the tone produced by a set of pipes is governed by how the pipes are constructed - the materials, the tone-producing mechanisms, the shape of the pipes, and the ratio of their diameters to their lengths.

By the way, Casavant Op. 3530 contains 2056 pipes, arranged in 41 ranks - a rather medium-sized instrument, but very complicated all the same.

In the next article in this series, I'll take a brief look at how the sounds of the organ are actually produced.

Part Two - Pipes, Ranks, and Actions

You'll probably recall that in the previous article in this series, I described the organ as a "box of whistles" - that is to say, a collection of pipes producing various kinds of "tone-colours", under the control of the organist. In this article, I'll look at some of the different kinds of pipes and how their sounds are produced.

There are two basic kinds of organ pipes. The first is called a "flue" or "labial" pipe (the latter name being derived from the Latin labium, meaning "lip"). These pipes really are whistles, and in their construction they greatly resemble a tin-whistle or recorder, with the "mouthpiece end" facing downward toward the wind-chest. A great deal of skill and science goes into the design of the "mouth" of the pipe, which is where the stream of air from the chest is set into vibration as it emerges from a narrow gap (the "flue") and passes over the edge of the "lip" or "labium". Much of the pipe's tonal character results from the design of its mouth. The vibrations, which start here, then activate the column of air in the remainder of the pipe (its "body"). This serves as a resonator, and thus forms and shapes the pipe's tone, as well as determining its pitch. Some flue pipes are constructed of wood and others of soft metal; some are open-ended and others are closed (or partially closed) at the top. These pipes produce the tones that listeners often hear as being most characteristic of the pipe organ. Depending on the construction features and diameter ("scale") of the pipes, they can be classified into three families, referred to by organists as the "diapasons" (die'-a-pay'-sons), which are the foundation of the organ's sound, the "flutes", which have a softer and smoother tone, and the "string-toned" stops. This last group is so constructed as to have a somewhat "burry" quality of tone that imitates (to some extent) the stringed instruments of the orchestra.

The second family of pipes, being the "reeds" or "linguals" (Latin lingua = tongue), is constructed more along the lines of a typical New Year's noisemaker. Rather than having something resembling a whistle mouthpiece at the base (or "foot") of the pipe, members of this family have a metal tongue or reed, which, under the influence of the stream of air from the wind-chest, vibrates against the side of a "shallot". This mechanism is concealed within the "boot" at the base of the pipe, but, when exposed, looks rather like a little metal saxophone mouthpiece. As with the flue pipes, the reed's action sets into vibration the column of air in a "resonator". Depending on the wind pressure, the construction of the reed and shallot, and the size and shape of the resonator, these pipes can produce a wide variety of sounds - most of which are named after the orchestral instruments which they suggest: "trumpet", "trombone", "oboe", "bassoon", etc.

Incidentally, it's worth noting that all organ pipes are hand-made from scratch. Each is created as part of the design of the specific organ for which it is intended, taking into account how the pipe must blend into its rank, and how that rank must fit in with the tonal design of the entire instrument in its intended environment. Pipes are definitely not assembly-line items!

As I mentioned in the first article in this series, the pipes are arranged in groupings called "ranks" atop the wind-chests of the organ. Each rank consists of pipes that all produce the same kind of tone-colour; ranks can be called into play individually, or in various combinations. Each rank is associated with a control called a "stop" at the organ's "console" (which is where the organist sits!); the stops allow the organist to select which ranks will sound when a key or pedal is depressed. The combined mechanism for actuating stops and for connecting the playing keys and pedals to the wind-chests in the pipe chambers is referred to as the "action". In old organs (as well as in many instruments of modern construction), all of this work is accomplished mechanically through linkages that extend directly from the console to the chests (generally referred to as "tracker action"). However, in many organs built since the end of the 19th century (including our Casavant Op. 3530), the selection of which ranks will sound and the actual control of the individual pipes is accomplished through a combination of electrical remote controls, and electrical and pneumatic actuators inside the wind-chests (called, with good reason, "electro-pneumatic action"). This arrangement has the dual advantages of allowing the console to be located at a greater distance from the pipe chamber, and of allowing it to be moved about within the limitations imposed by the length of an electrical cable - as you may have seen if you have attended an organ recital at the Cathedral. However, many organists still view a tracker action as the ne plus ultra of organ construction because it gives them direct control over both the "attack" (start) and "release" (finish) of each note. This fine control of "pipe speech" gives the player much more flexibility in "articulation" - the transitions from one note to the next which occur in the course of playing music.

In the next article of this series, I'll look a bit more closely at how the ranks of pipes are configured in an actual organ, and how everything is powered.

Part Three - A refuge for Imperial measure, and a source of wind

In the previous article in this series, we looked briefly at the various kinds of pipes in the organ, and how they produce different tone-colours. This time, we'll continue the discussion of the pipes and their arrangement, and consider the air that operates them (the "wind").

In most cases, drawing a single stop and then pressing a single key at the console will cause a single pipe to sound, up in the pipe chamber. Stops are characterized by names (e.g., Principal, Trumpet, Harmonic Flute), which correspond to the tone quality of the ranks that they activate, and "footages" (e.g., 8', 16', 4') which correspond to the pitch at which the ranks sound. This last may require some explanation!

As it turns out, the pipe-length of the lowest "C" of an open flue rank of "normal" pitch (that is, one which gives the same pitch when played from an organ manual as would the corresponding key on, say, a piano) is almost exactly eight feet - hence, this pitch is referred to by organists as "eight-foot" pitch. Some pipes sound at an octave above this normal pitch; by the same reasoning, these are referred to as having "four-foot" pitch. Some even play two octaves above (2'); some play an octave below (16'), and on some organs, some even play two octaves below (32') - although there are none of these on Casavant Op. 3530-for reasons of expense, and because of space limitations! When played together with pipes of normal pitch (by "drawing" several stops together), the higher octaves provide additional brightness; the lower octaves provide additional fullness and "gravity"-and of course, when more pipes are playing at a given time, the total sound that is produced is louder. The sound also becomes richer and more complex as more ranks are employed, because of the complicated interactions between all of the pipe-sounds!

One of the major tasks of designing and installing an organ is to ensure that all the ranks of pipes will blend properly when they are played together. The "tonal architect" (mentioned in the first article of this series) begins this job by selecting the tone-colours which are to be employed; the organ-builder's "tonal director" and a staff of in-house designers continue the work by "scaling" and "winding" the ranks to determine their relative loudness; and the "tonal finisher" completes the task on-site when the organ is being installed - an adjustment process which takes weeks, or even months for a large instrument. (By the way, another occupational term you may hear from time to time is "voicer" - the job of the voicer is to ensure that all of the pipes of a given rank blend together perfectly, and that they all produce exactly the same tone-colour - yet another highly skilled and demanding task!)

Most pipes do sound the note which one would expect when the key is depressed, in one octave or another. However, to provide reinforcement for certain harmonics (and thus to give additional tone-colours), certain pipes sound at intervals other than an octave above the note associated with the key that is pressed. I won't go into too much detail here, but one of the most common of these is 2 2/3' - sounding an octave plus a fifth above the fundamental note, and thus reinforcing the third harmonic. Such ranks are referred to as "mutation stops". Related to these are the "mixtures" - these consist of several ranks which always sound together (and which are drawn as a single stop), thereby reinforcing several upper harmonics at the same time. In some of these on Casavant Op. 3530, five pipes sound for each note! Mixtures and mutations are always drawn with unison-pitch stops (rather than by themselves). They are perceived by the listener as providing additional "character" or "sparkle" or "brilliance" - you would be hard-pressed to identify their individual notes even if you were actually standing inside the pipe-chamber.

By now, you may be wondering about the source of all of the air that must be needed to run the organ. Surprisingly, (and contrary to popular belief) everything in the organ operates on very low air pressures - in the case of the instrument being considered here, equivalent to a soft breath! Pressures in the organ world are measured in "inches of water" - the height of the water column that would be supported by the air pressure. All of the ranks in Op. 3530 are voiced on pressures of only a few inches.

For this reason, everything can be powered by one small blower - sort of like a large furnace fan, turned by a one-horsepower electric motor. It's located in a closet in the vestry area, directly below the pipe chamber. The flow of air is smoothed out by a system of weighted bellows and regulators - the main bellows is located in the pipe chamber and is about six feet square. It serves to store air that might be required for particularly loud passages and large chords, and to smooth out the pressure fluctuations that might otherwise be caused by changing demands for air. The "winding" system is also the source of one "special effect". A device called a "tremulant" can vary the pressure to a group of pipes several times each second to produce a "wavering" or "trembling" of the sound of any stops that are drawn along with it.

We are almost done with our brief description of the organ - the final article in this series will attempt to describe how everything fits together!

Part Four - Three organs in one?

If you have ever had a look at the console of the instrument at St. John's, you will have noted that there are two keyboards (or "manuals", or "manual claviers") of fifty-six notes each, one above the other, and a pedal-board (or "pedal clavier") of thirty notes, located at the organist's feet. In this instrument (as with most church and concert organs), each one of these controls a "division" in the pipe-chamber, which constitutes almost a complete organ in itself. (I make this distinction because theatre pipe organs - such as the "Mighty Wurlitzers" found in old cinemas such as Shea's Buffalo and the Radio City Music Hall - are a different kettle of fish altogether . but I won't get into that in this forum!)

The lower manual controls the "Great Organ", which contains a lot of the more solid-sounding and louder ranks. The pipes of the Great are unenclosed - you can see them on their chests, sticking right out into the chancel. The only way to produce louder and softer sounds with the Great is to draw more, or fewer, of its stops.

The upper manual controls the "Swell Organ", which has nearly as many ranks as the Great; the Swell, however, differs in that it is completely enclosed within a large box that has shutters which operate after the fashion of vertical Venetian blinds. Keen observers will have noticed these shutters opening and closing inside the pipe-chamber; they allow the Swell to produce louder and softer sounds without changing the number of stops drawn. The shutters (or "shades") of the swell-box are controlled by a "shoe", located above the pedal-board, and inset into the front of the "keydesk". The swell shoe looks almost like an accelerator pedal.

The pedal-board controls the "Pedal Organ". It contains ranks that form the "bottom" of the musical harmony - that is to say, while the chief stops of the Great (for instance) are of 8-foot pitch, the chief stops of the Pedal are of 16-foot pitch - an octave lower. The ranks of the Pedal are unenclosed, like those of the Great Organ.

There are also other controls on the organ console:

Stop Tablets - These are the controls that call into action the various ranks of pipes which are at the organist's disposal. They are located (along with the Couplers, q.v.) in a row above the Swell manual.

Couplers - these allow the organist to couple the various claviers together, to allow, for instance, stops from the Great to be played from the Pedal, or to allow stops from the Swell to be played from the Great.

Thumb Pistons and Toe Studs - These are buttons that can be used to "capture" a combination of stops, and then invoke it again almost instantly by a single thumb-press or toe-tap. They allow the organist to change the stops that are drawn (the "registration") very quickly. The device that actually stores the combinations and then actuates the selected stops is called the "combination action". The pistons are located on the "key-slips", which are the wooden strips below the keys of the manuals, while the studs are located along the front of the pedal board. Two special pistons (duplicated as studs) are the "Full Organ" or "Sforzando", which brings almost all of the organ's stops and couplers into play at once, for a sudden loud sound, and the "Cancel", which has exactly the opposite effect, silencing everything so that (for instance) the organist can get off the bench without making an unintended racket.

Crescendo Shoe - This is a "shoe" located right next to the one which controls the Swell shades. As it is depressed, it gradually calls more and more stops into play so as to produce a louder and louder sound - so that when it is "floored", almost every stop and coupler is engaged. The Crescendo is seldom used, but can be very effective.

As I mentioned in the first article of this series, Casavant Op. 3530 is a medium-sized instrument; organs often have anywhere from three to as many as six or (very rarely) seven (!) manuals, with, in the very largest instruments, tens of thousands of pipes in two hundred or more ranks! At less than twenty years of age, Op. 3530 is still relatively youthful as pipe organs go; given appropriate care, cleaning, and maintenance, a well-built instrument can last fifty or more years without major reconstructive work, and there are playable organs which are, literally, centuries old. Any pipe organ is an investment that is worth preserving!