Understanding the four types of pipe organs
  • As a short guide:

    Tracker Pipe Organ - expensive, possible life span without major work required - at least 100+ years or more. Trackers are the only organs you hear about that can last for centuries with minimal maintenance. Occasional minor reservoir releathering may be required every 25 - 35 years. Console must be close to pipes.

    Electropneumatic Action Pipe Organ (EP) - medium expense, tonally rich due to air channeling, major, expensive work required every 25 - 35* years to releather pouches and maintain in top operating condition. Use of digital circuitry now common in control systems, may need replacement* at same times as releathering. Console and pipes need not be placed near each other.

    Electric Action Pipe Organ (EA) - least expensive, quite reliable, may not be as rich tonally due to action type, periodic but very affordable work required every 25 - 35 years to releather reservoirs. Use of digital circuitry now common in control systems, may need replacement** at same times as releathering. Console and pipes need not be placed near each other.

    Combination Pipe/Digital Organs (Combo Organs) - Use digital circuitry now common in control systems but also include additional digital stops, all expenses for EP and EA listed above apply. Console and pipes need not be placed near each other.

    *Prior to 1927 the process used in tanning leather resulted in long-lasting pipe pouches, some, if not many, still workong and playing today. Organs built since then have had to use lesser quality leather, hence the short life span.

    **many builders use digital circuitry from small, boutique digital design houses, making future availability of parts and support doubtful, as has been proven in situations. Sticking with major suppliers with long track records and financial stability, such as Peterson, Syndyne and others, help eliminate this possibility.

    Hope that this is helpful!

  • donr
    Posts: 944
    This is great information, thanks
  • Adam WoodAdam Wood
    Posts: 6,350
    This is fascinating.

    I don't follow the difference between Electropneumatic and Electric Action, or how that affects tone. Can you explain that a little further?

    Also - whatever happened in 1927 to change how everyone in the world tans leather? Does no one make it the traditional way?
  • CharlesW
    Posts: 10,510
    With pipe organs, cleanliness is next to godliness. When my instrument was releathered, after 50 years of use, I had the blower room cleaned and air filters put on the air intakes. One of the big causes of leather failure is dirty outside air. Maintaining a minimum temperature in the building during winter lessens environmental stress on many instrument components. Some folks simply don't take proper care of their instruments, which causes them to fail prematurely.
  • redsox1
    Posts: 197
    The new chromium tanned leather is much better and has a longer life span. Also, I guess Kangaroo leather is even better since it more supple.

  • Liam
    Posts: 4,050

    Interested in heavy metal, are we? I once lived for 4 years on property in the northernmost block of Cambridge, MA that was once the site of a tannery in the 19th century. Let's just say things did not grow particularly well in the soil there.
  • Electric action (EA) admits air directly to the foot of the pipe.

    EP and Tracker admit air to channels over which sit all the pipes that might be played by that key when they are activated. The air moves at the speed of air, creating turbulence and also is thought to undulate along with the pipes as they play. For this reason there are those who feel that the direct route of air to the foot of the pipe on EA organs does not produce pipe sound to the quality the EP organs does.

    To complicate things, organs are built that use of EP and EA for different divisions or offset pipes...and now builders are also driving the air on EA organs through wind channels to improve their sound which does raise the price a bit.

    There are even tracker builders (no electricity required except for the blower) who build pedal divisions with EA action and also include electric couplers between manuals to reduce the weight when coupling.

    Some EP builders are also successfully using "slider chests" originally found in tracker organs, to reduce the number of leather pouches that are prone to failure.

    Why the difference in price? An EP chest is a warren of tiny channels and passages crafted in wood to route the air to the pipes. You build an EA chest by making a simple airtight box, then drilling holes where you want the pipes to sit and then screw in the little EA action valve and hook up two wires to it.

    As far as leather, when I worked with Möller we would see organs with pre-1927 leather in perfect condition - as far as chromium tanned leather, only time will tell. An attempt to use manmade material (perplex) almost brought about bankruptcy for a number of builders - most were able to stay in business, often by asking the church to help bear the expense of replacing the perflex with leather. More info about perflex.

    And about leather tanning : here
  • GavinGavin
    Posts: 2,799
    Not to mention that builders who use Direct Electric action (properly called "snake oil salesmen") often resort to unification to artificially increase the size of an organ (I'll let Freud discuss this one), which is a most lamentable trend due to the missing notes.
  • CharlesW
    Posts: 10,510
    I had heard Kegg had developed a new type of electric action that gets around many of the problems associated with that type of action. Info on this, anyone?
  • Unification and duplexing, like the poor, have always been with us.

    Duplexing is using a rank of pipes playing at one pitch on a keyboard and then at a different or same pitch on another keyboard. Often you will find a soft 16' like a Lieblich Gedeckt stop playing on the Swell and also available on the Pedal.

    When used on a different keyboard at a different pitch it has a different tone color - since pipes usually change in tone color as they rise in pitch - it's called scaling.

    Unification takes one stop and, by extending the pipework to play an octave lower and an octave or two higher, permits that pipe rank to be wired to not one stop, but as many as 7 stops on the same keyboard - and also to be available at various pitches on a different keyboard. I played a Robert Morton theater organ with 4 sets of pipes playing from more than 50 stop tablets...

    This explains why theater organists - often double the melody by playing octaves - unification is "bad" because a pipe only plays once....so there are notes that have fewer pipes playing when playing a chord on a unified organ...

    How to test for unification (important because often names for a stop are changed even though they use the same stops) is simple. Play CEG as a chord starting with middle C. Select an 8' stop - a flute for example. Without letting go, play the 8' flute on another keyboard, first with Db F Ab then C E G. You will hear the first three notes play and the second chord of CEG if it is "straight", meaning not borrowed. If the second chord does not sound it is because that stop has been unified from the first stop you played and the pipes are already playing.

    Then, still holding the first chord, try the 16' flute on the second keyboard playing up an octave, the 4' down an octave and then the 2' down another octave.

    Why is this a problem? Unification, especially when playing hymns, emphasizes the top and bottom notes being played but not the middle ones. Lack of balance.

    Theater organs were highly unified because it made a lot of stops cheaper to buy...since they make the organ look large. The other large buyers of unified organs were Catholic churches, for the same reason - low price for what appeared to be a lot of organ.

    Sales people who sold these organs were not all shysters...all builders, including Aeolian-Skinner, used unification and duplexing in very judicious ways. Small organs especially benefit from unification since it provides more stop combinations that are possible in a church where 5 or 6 stops are all that can be afforded.

    Judicious stop choices can produce great effects on a unified organ - rather then being stuck with just 5 or 6 stops.

    EA organs are very easy to unify, once again making them the choice of many Catholic church pastors. EP organs duplex easily. Tracker organs are difficult to duplex and almost impossible to unify.
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  • Why trackers are not always the best choice in a used organ.

    EA and EP organ chests can be reoriented in a new church but trackers are one-piece organs, meaning that everything is mechanically connected and any changes, usually impossible, can be very difficult - there was a 28' wide tracker available here brought down from Boston and it was offered to many churches - the one I was at had a 24' wide loft and it would not fit.

    Adding more stops to a tracker - same problem.

  • redsox1
    Posts: 197
    Most builders who use EA are using expansion chambers between valve and pipe foot that mitigate the effects of turbulence. In conversations with both Charles Kegg and Pat Murphy, there are voicing challenges, but these can be overcome. There is nothing wrong with judicious unification and duplexing, but I agree with Gavin that this practice can easily be abused. Choruses must be independent!

    EP slider seems to be the way to go these days. Check out Goulding and Woods chest design. It's quite ingenious. You get the simplicity of note channels, the speed of a pneumatic fired pallet and a much reduced need for leather. IMHO, this type of action is superior to electric pull-down slider chests.

    I remember well when all those Perflex chests began to fail. Too bad it didn't work!
  • BruceL
    Posts: 1,027
    TCC/NJ: did you have any hand in the Moller here at the cathedral in Birmingham? I'm very thankful every day for it, although I curse slider chests anytime I pull a stop (ker-chunk). I was hoping it was all solid-state, but indeed there is a good bit of leather. Only other "firstworldproblem" is that we have only four memory levels. Otherwise, with a new cromorne and a few other tweaks, it's fantastic.
  • Austin Organs' Universal Windchest is yet another variation--in this case proprietary. And the traditional form of these chests is large enough for a technician to stand upright in while the organ is pressurized and to work on all the moving parts directly. Quite an experience!
    Thanked by 1BruceL
  • Milnar Organs in Eagleville, TN has a similar action adjustable windchest in which the bottom board is not screwed in with thousands of screws but is plexiglas and up in the chest so the air pressure keeps it down in place and adjustments to the action, much like the Austin, can be made while the organ is being played - see the problem, push the plexiglas up, adjust, drop plexiglas back into place and test. Brilliant design!
  • Before my time - I was there for the final incarnation....wonderful organ from all that I have heard - I must come visit!
  • Now what we need is a discussion about how the different playing actions respond under the hands. I don't think that I could ever recommend an electric action organ again, to be honest.
  • Yes, some of the finest EP and EA organs, including Casavant, have used a toggle switch arrangement to give the feel of tracker touch - the initial stroke has to overcome this tension and then the key falls freely to the keyed, just as the tracker requires you to overcome the tension of the air resisting the palette from falling away and admitting air into the channels under the pipes.

    This "tracker" type action matches the stroke required of the harpsichord required to pluck the string - and then the key falls to the keybed, just as it does on the piano.

    However, this is very important. On the harpsichord when the key hits the bed there is an audible thump unless the player strokes the key towards them to eliminate the loud thump.

    The piano has the same thump but plays so much louder that it is rarely heard.

    Why is this important? Early organists spent most of their time playing and compsing even for the organ on the harpsichord and clavichord - which also thumps, because they had to pay someone to pump the organ. So it makes perfect sense that organ technique that they wrote for is based upon the stroke and not downward pressure. The stroke permits much cleaner playing, especially on 16th notes....they sparkle.

    I sincerely doubt that there was a "different" organ technique from this - if there were, they would have written about this.

    So there are builders that see the modern EP and EA actions as needing the "tracker touch". I never do a design without it, especially on digital consoles.

    Digital organs can play more like tracker organs that EP and EA when voices properly and need the tracker touch to work well under the fingers, but that's just my humble opinion.
    Thanked by 1CHGiffen
  • canadashcanadash
    Posts: 1,454
    Why trackers are not always the best choice in a used organ.

    I understand that they can also contribute to carpal tunnel syndrome because the action can be so heavy?
  • If the action is not properly balanced, they can get heavy.

    At the same time, I am wondering if the stroking action of the harpsichordists - pulling towards you rather then a straight downward stroke which locks at the bottom - might be less prone to cause hand problems since the muscles of the fingers that contract and expand instead of being forced into a locked position with arm weight involved in what is considered typical organ touch.

    I have an interest in all of this because of playing the harpsichord but also playing the cello in which there are definite right and wrong ways to use both hands and arms....and I've been prone to do it all wrong!
  • canadashcanadash
    Posts: 1,454
    My son plays cello and has a strict teacher. I'll ask him.
  • About heavy tracker actions, I have always relished a heavy action as an added benefit for strengthening one's fingers and attendant muscles. I enjoy the challenge to master it. Every good organ has attributes which require coming to terms with, but, when one forms a bond with such an instrument is when he(she) can enter into new realms and dimensions of the musical craft and liturgical art. It IS another world.
  • On the Pasi organ at the Co-cathedral in Houston, 3 of the 4 manuals are tracker and one is electronic. What is unique is that it still has trackers attached to if to make it feel right (not just tracker touch, but real trackers). It then uses optical sensors to monitor the key press much like modern midi keyboards. Then on the remote decision it controls, there are servos that mimic true tracker action by opening precisely with the depression of the key.

    Truly a feat of engineering.
  • CharlesW
    Posts: 10,510
    You can have those trackers, and tracker touch. I don't want any part of either. Rampant archaeologism! Might as well park my car and ride a horse, if we are going to live in more primitive times. Interesting that great French organists were impressed with American consoles in the early 20th century, because the French consoles were so primitive. Yes, I know there is a whole school of thought related to authentic early organ performance practice. I would rather approach that from the position of what Bach might have done, if he had organs with decent actions. Eyewitnesses indicate he played organ very slowly. Probably had to.
    Thanked by 1R J Stove
  • Tracker actions do permit you to control the exact moment the pipe speaks, which if you are into power and control, is cool.

    But when you play multiple stops, you lose control again, as pipes of different styles speak differently - as well as those of higher and lower pitches. That's why some like tracker manuals but use electric couplers between the manuals.

    As far as speed, the more live a building, the slower tempos need to be...so what seems like a contradiction - Bach playing slowly - may well be very true.
    Thanked by 3BruceL CHGiffen francis
  • CharlesW
    Posts: 10,510
    I suspect his slow playing had something to do with heavy, primitive, slow tracker actions, too. With newer materials and engineering, tracker actions likely perform far better today than they ever did in the past.
  • BruceL
    Posts: 1,027
    I'm sorry, but if you can't appreciate the nuance that is possible with a (good, well-regulated) tracker action on a piece with basic registration (a Stanley voluntary, a piece from the Spanish Baroque school, Frescobaldi, etc.), there is a deficiency in your training (to be blunt!) I can't say those are my favorite repertoires, but the difference in playing that on an excellent EP organ (I am very fortunate to have one of these, and would not trade it!) versus a tracker is mind-boggling. The tracker also will keep your technique much sharper. I have to work very hard to get articulations in Baroque music that would be second-nature on a tracker.
  • CharlesW
    Posts: 10,510
    To each his own, and my training was fine! This is all the organ fad of the moment. Anyone remember 8' instruments and how everyone who didn't appreciate them was illiterate and uneducated? The fact that you can play something a certain way on a modern tracker doesn't mean it sounded the same on a more primitive instrument. Then there is the assumption that all want to play Baroque music. Not true!
    Thanked by 1R J Stove
  • kevinfkevinf
    Posts: 1,111
    Give me Barker levers anyday.
    Thanked by 2CharlesW eft94530
  • BruceL
    Posts: 1,027
    So, @Kevin in Kentucky, you want reduced control vs. a tracker, and more noise than EP? ;-)

    I do think the recordings of scherzos at St. Sulpice are charming with all the BL's a-clattering, making as much noise as the quiet stops that are on! C-C's instruments are unbelieveable...all that technology before there was even electricity...and they're musical to boot!

    @CharlesW, the question isn't our preference: it's that our ear should hear a difference regardless of opinion. My premise is that (even if you don't like the repertoire, or trackers) if you can't hear a difference, that will play itself out in the musicality of the interpretation, etc. Virgil Fox may not have liked trackers, but you better believe he would have exploited their musical advantages if he was playing on them!
  • CharlesW
    Posts: 10,510
    I can hear the difference, but am not a great fan of Baroque music in general. Specifically, I rather like the French Baroque, but finding a replica instrument would be difficult. It likely would not be as useful for service literature as a modern organ. Then there is the fact that those English, Spanish, Italian, and French instruments did not sound alike. The fact that they were trackers may have been about all they had in common.

    I am actually old enough to have heard Fox play several times. He was always fascinating, and often unpredictable. A master showman, always! (I heard Flor Peeters play in my youth. A memorable experience that I still haven't forgotten.)
    Thanked by 1R J Stove
  • kevinfkevinf
    Posts: 1,111
    @BruceL. Play a CC and you will appreciate the touch. Yes, they make noise, but ooh la la, they make it fun. I did not understand until I played a CC.

    Seriously, the type of action and choice should be practical. There is a Bedient in Memphis with very long trackers (I think 20 feet) and it is not fun. Build the instrument that will work for your space. Trackers, EP,Direct electric. They all disadvantages and advantages.

    BTW, BruceL, one of my dear friends helped with your instrument in Birmingham. Have not heard the instrument in quite a while.
    Thanked by 1BruceL
  • The trackers at Idlewild are no longer. The organ was almost unplayable--I played it just a bit before the work took place and it was a hot mess.

    When they were electifying it, they also put the pedal board on an elevator--which I hadn't seen in person before.
  • Can someone explain slider chests in more detail? I was under the impression that it was sort of the best of both worlds in a modern organ, no? Are sliders only found on trackers and EP, or can they be used on EA as well? Unfortunately, I've not had the opportunity to play on too many different organs to form an opinion on how they feel, but in terms of sound, I can definitely hear the difference between EA and EP, and having an affinity for early music all the pops and clicks of a mechanical action don't bother me a bit (when listening to early music) though I can imagine that trackers may not be ideally suited to contemporary literature.

    Seriously, I have the opportunity to oversee the install of a new organ, so I want to learn all I can about the mechanics. In terms of tone color I prefer a rich, warm tone (i.e balanced, not tubby but not too bright). The EA organs that I have heard/play all seem too thin for my ears. Feel free to PM me if you want to comment on a specific builder for better or worse.
  • As an easier explanation of unification: A four rank pipe organ can have four stops or forty stops.

    The four rank four stop organ is like having a flautist, tenor sax player, violinist and trombone player.

    The forty stop organ is like having four instrumentalist who can "double": a flautist that can play alto flute, piccolo; Sax player who can play baritone, alto, tenor, soprano; violinist who can play bass, cello, viola; trombonist who can play tuba, euphonium, bass trombone, trumpet, cornet and piccolo trumpet. But you still only have four players. Or four ranks of pipes.

    Hope that this helps what can be a confusing subject.
    Thanked by 1ClergetKubisz
  • Adam WoodAdam Wood
    Posts: 6,350
    ok, so i get mechanically how an EA is different from an EP.
    What makes the different method of air delivery cause a difference in tone?
    Does it have to due with air-pressure regulation? The gradual opening of the pipe as the leather moves? Nothing inherent, but causally related to poor craftsmanship?
  • matthewjmatthewj
    Posts: 2,641
    I love listening to tracker organs, but it's just too much drama for me. I like to be able to actually enjoy doing my job... and my wife doesn't want to hear me complain for an hour when I get home from work.
  • CharlesW
    Posts: 10,510
    The EA organs that I have heard/play all seem too thin for my ears.

    That sounds more like a voicing issue than the type of action.
    Thanked by 1Earl_Grey
  • Action explanations with useful drawings

    As you can see, the Direct Action lets air directly into the pipe foot. All other actions have the air travel a distance that may involve going around corners - all of these factors, including resonance of air in the air channels of pipes that are one the same pitch or in the harmonic series of that pitch - make the pipes sound different than when played on a DE - or since Direct Electric™ is a Wicks registered term, Direct Action as shown here - the same thing.

    Voicers find it more difficult to voice DE/DA chest pipework - which may be why they can sound "thin" - but this also may merely be the scaling choices of the builders. When I was with Möller we often added a new Principal 8' to mid-60's Möllers with a new drawknob, replacing the old Principal draw knob that read Viole da Gambe...without having to revoice the old Principal pipes - it was a scaling choice of the designer back then.
    Thanked by 2CHGiffen Earl_Grey
  • Dispelling the notion that we know how the organs sounded at Bach's time.

    Lawrence Phelps got tired of hearing, "Oh, I heard/played one of the Schnitger Organs and I got to hear how organs sounded when Bach was alive.

    Phelps have two identical pipes made and voiced identical. Then locked one in a draw and then had the other one rigged to play for 6 months (in a sound-proof closet).

    At the end of the six months they were both mounted on a voicing chest, side by side. It was impossible to return the pipe that had played that length of time to sound just like it's brand-new, played a couple of times and stuck in the drawer full-brother pipe.

    The metal of the pipe was changed by being played.
    Thanked by 1CHGiffen
  • Where the sound of the pipe comes from.

    Phelps proved with cigarette smoke and slow motion cameras that when smoke is added to the air in the blower, as notes are played what look like vibrating reeds appear in the air in front of the mouth of the pipe. The sound of the pipe is not in the pipe but in front of it. The length and width of the pipe cab produce resonance and determine pitch and tone color, but the actual sound happens out in front of the mouth of the pipe.

    The air in the pipe does not go out the top - instead it is a pulsating column of air - when a bit escapes from the top, that creates a vacuum and a bit of air is sucked into the mouth, which then creates a vacuum at the mouth which then pulls the air down from the top - pulsating at the pitch of the note.

    Reed pipes are different, as there is no mouth and the reed in the boot of the pipe then sends its sound up through the pipe where it then escapes at the top of the pipe. Does it appear as a vibrating reed there? Bet it does.
    Thanked by 2CHGiffen BruceL
  • Check out Goulding and Woods chest design. It's quite ingenious.

    You can if you come to Colloquium next year. St. John's has a G & W.
  • redsox1
    Posts: 197
    Scaling and voicing make or break an organ of any action. An EA action is no less capable of providing a satisfactory result than EP or EP/electric slider actions IF it is skillfully built.

    I LOVE a good mechanical action. The Fisk organ at Mt Holyoke is one of my absolute favorite instruments. The action is a dream and early music comes to life, especially with its spicy temperament!
    I think, however, that you start to lose the sensitivity of the action if the instrument is much larger than about 20 stops, or if the action involves really long runs. At that point, you're better off saving your money and building a first-rate action of another type, especially in a liturgical setting.
    Thanked by 1BruceL
  • Adam WoodAdam Wood
    Posts: 6,350
    proved with cigarette smoke

    "the devil's incense" -J. Tucker (in an excellent essay about Casinos)

    "I almost didn't write it, because I didn't want anybody to think I was anti-smoking or anything" -J. Tucker (in a personal conversation, later)
  • BruceL
    Posts: 1,027
    @Kevin in Kentucky: We're trying to take good care of it! It suffers from bad zinc (as do many of those organs), so that's going to be at least $50-75k when we get around to it. It's not my favorite tonal design in the world, but I'm a big fan for the most part. It is very fun to play. I need to get the action regulated and I would love to get a new krummhorn (the one that's there runs out of gas at middle c and has a scale about as big as a #2 pencil!), but otherwise I'm tickled...and in that room! I am thankful every day.
  • kevinfkevinf
    Posts: 1,111
    @BruceL: I went to school in B'ham and the cathedral was my parish. But it had an old Rodgers then. So much has changed. Great place now. Tis jealous of you....

    Back to organs (and actions and Barker levers and builders)....
    Thanked by 1BruceL
  • Perhaps someone with knowledge of organ actions can answer this question for me. I recently began a new position in a church that has a very nice Schantz organ, EP action of course. I had been playing a tracker action for the past 13 years. The Schantz was built/installed in 1964 and has been properly cared for but is now due for an overhaul to solid state, and the other usual upgrades of a 50 year old EP organ. My question: regardless of this imminent overhaul, is it a common among EP action that it can seem sluggish (in response time) when playing something of a fast tempo? It was on a toccata that I played that I had difficulty, it seemed that the response from the pipes couldn't quite keep up with the tempo of the playing at the keyboard. I had to actually reduce the tempo in order for the piece to play well. I should mention the room is pretty dry acoustically, and the pipes are placed about 12 feet from the console. Is this something I can expect to be improved with the overhaul? Any suggestions?
  • CharlesW
    Posts: 10,510
    I know this may sound a bit odd, but when my Schantz was rebuilt in 1994, they worked on the contacts in the console, which had become worn over time. That speeded response time up. This is such a simple thing it could be overlooked.
    Thanked by 1BJJ1978
  • Thank you, Charles, I made a note of that. Also, how long were you without the organ during its rebuild?
  • CharlesW
    Posts: 10,510
    About a month to 6 weeks, as best I remember. Schantz did the rebuild and we lived with an Allen down front. When they shipped chests back to Schantz, the loft was a cluttered mess. We had to sing from the front.
  • The major advantage of tracker action over all others is that being totally mechanical, it can be repaired or rebuilt by any organ builder centuries from now.

    The modern electronic control systems, specifically the digital variety will need replacing eventually, as the manufacturers of the various parts will go out of business or be bought out and the spares will be unobtainable in the long run.

    An analogue wiring system would be better in this case, but with hundreds of wires and diode matrixes, etc. It would be a pain to trace faults should they develop.