What About The Piano
Piano skills can be a great help to the new organist, but the question of how much study of the piano is necessary before one moves to the organ can elicit a variety of responses. Theoretically, it's none. Depending on what you're wanting to do with it, it's entirely possible to play the organ without ANY piano training, whatsoever. The common thought is, as long as you can read music you can learn organ, provided you can find a good teacher. But from the perspective of someone who started at the organ and then had to play "catch up" at the piano, I can tell you that practicing even one Czerny etude (The Art of Finger Dexterity, Op. 740, the first one from this book, in C Major) at a piano will strengthen your fingers, develop them equally, bring the left hand up to speed with the right hand, and provide an evenness you might not have otherwise, unless you're privileged to work first at a pipe organ with a heavy mechanical (tracker) action. It might be possible to get the same dexterity in these situations because on some tracker actions it's harder to play fast than at any piano, but this could be splitting hairs.
Oddly enough, there are some piano majors who can't play well on the organ because they don't have their finger muscles developed enough. When this happens it's typically because of overusing the sostenuto pedal, or center pedal, of the piano (see photo). In this situation it helps to play some polyphonic pieces, like the Bach Inventions, on the piano without any pedal.
NOTE: All pianos are supplied with a sustain pedal (commonly called damper pedal, or right pedal) and a una corda pedal (commonly called soft pedal, or left pedal). The sustain pedal, when depressed, raises the dampers on the strings and allows them to continue vibrating when the keys are released. When the sustain pedal is released the dampers engage the strings, and the sound ceases. The soft pedal is somewhat of a misnomer, as it primarily modifies the timbre, not just the volume of tone (on the modern piano the effect on the timbre is more subtle than on earlier pianos). When depressed it either brings the hammers closer to the strings (in an upright piano) or shifts each hammer slightly to one side of the strings (in a grand piano) so that, in the double strung bass octaves only one string is struck and in the triple strung treble octaves only 2 strings are struck. Where the lowest bass notes are a single thicker string the action lifts the hammer so that it strikes the string on a different, lesser-used part of the hammer nose. The effect is to create a more ethereal tone and, at the same time, the tone is softened.
When a third pedal is supplied it's called a sostenuto pedal (commonly called muffler pedal, or center pedal) and was the last pedal to be added to the modern grand piano. This pedal holds up only those dampers which were already raised at the moment it was depressed. If a player would hold down a note or chord and while doing so depress this pedal, then lift the fingers from that note or chord while keeping the pedal down, then that note or chord would not be damped until the foot is lifted despite any subsequently played notes being damped normally on their release by the fingers. This pedal finds use in playing piano transcriptions of organ music where the selective sustaining of notes can substitute for the organ's held notes in its pedals.
An even more important thing, perhaps, for pianists to start doing when they move to the organ, is to get their feet moving NOW. They shouldn't lose a moment with that. There are many who will tell them, regardless of when they begin organ lessons, to make sure they're learning to play with both feet, heel and toe, on a real pedalboard, otherwise it can be argued that they're wasting their time at the organ.
If sombody wants to play organ, they should learn it. If they want to play piano, they should learn it. People may want to put me in the pillory for saying so, but the simple truth is, you don't need training in one to be able to play the other. Piano technique is completely different from organ, and vice versa. About the only things that carry over are finger strength and independence, phrasing, and stretch, scale, and arpeggio exercises. The old maxim "Master the 2- and 3-Part Inventions of Bach at the piano before you begin organ study" has been given much heed. I too, tend to quote this "Bach-Invention rule" when I'm asked about starting organ lessons because a) the Inventions teach you how to read music, and I don't typically want to see organ lessons used for that, b) it's like studying organ repertoire, since the Inventions transfer right to the organ and sound well when performed using suitable registrations, and c) the Inventions teach composition because they're actually 2-part and 3-part fugues. There are so many things to be thinking about when you're learning the organ, and it's hard to work on those at your lessons while also trying to learn keyboard and reading fundamentals. But then, by denying yourself any time at all at the organ, you find out very quickly that, while your finger strength, dexterity, and keyboard "feel" will carry over, the organ is a very different instrument. From my own experience I would suggest starting the organ ASAP and not to wait until you're at "an acceptable level" of piano proficiency. The two instruments are completely different, and I'm living proof that the piano is not necessarily a pre-req for learning the organ. I'd hate for someone to delay taking up organ because they aren't satisfied with their piano skills. I'd say if you have the ability to read piano music and love the organ, take it up. Even though one supports the other, they're two different, distinct instruments with little in common except the keyboard.
I also have to admit of my bias, that the organ has always been my principal and only musical instrument and that I've always used the piano as a means to get where I wanted to go with the former. At the same time, to be truthful and realistic, I see no real way to adequately prepare for, or to digest one's way through, ALL of the organ repertoire without some modicum of technique at the piano. The great art of organ playing escalates with the playing of repertoire, and the French model of study at the piano before the organ addresses this question rather well. To develop dexterity and facility for playing ALL the organ literature, a certain amount of work at the piano in terms of stretch exercises for the hand and the ability to play scales and arpeggios legato and evenly, in all their various combinations, is therefore something with which every organist, at some time or another, must come to grips. I did exercises, so did my teachers, and you should do some, too. It's true that not everyone is studying the organ to play Vierne's 5th, but facility at the piano conditions the hands and makes for a little easier study of the organ and its eccentricities.
Here's yet another twist to think about: It's a fact that there are organists out there who never took a piano lesson in their lives and they're top notch performers, playing repertoire that could put many organists to shame. They've been a church organist for years, and have been told many times that they play very well. If asked, if they ever lamented never taking piano lessons, the answer they give, typically, is something like, "Absolutely not. I wanted to study the organ, and did." Then again, sometimes we'll come across a person, who plays the organ so well that it seems quite obvious to our ears that they play professionally, who in fact doesn't play professionally and never did, and who never took any meaningful piano lessons either. What are we to make of this when, just the other day, we heard a person like this firing away the Toccata from Widor's 5th without flinching or dropping a note? ... except to say that some organists evidently have made up in other ways for never having taken piano lessons. It's good for an organist's hands to practice the manual parts of organ pieces like this on a keyboard with weighted hammer action for the finger strength and independence it provides, and this can be an actual necessity in many applications due to the unavailability of an organ for practice purposes. The bottom line for me is, I agree that learning the piano will definitely help prepare the hands, develop the fingers equally, give a basic knowledge of things, and provide some dexterity before coming to the organ, but overdoing it to the complete exclusion of the organ will likely take years of correction to organ technique. The two aren't the same. The fact is, you can skip certain frustrations when coming to the organ if you don't have extensive piano preparation ... in other words, you don't have a "piano way" of approaching the organ, you have instead an "organ way" of approaching it.
Pipe organs come in a huge variety of shapes and sizes, actions, tonalities of stops, temperaments, tuning, and national and historic methods of building, far more so than with pianos. Unlike pianos, pipe organs are wind instruments which have to be played according to how they breathe in their own particular acoustical environment. That is, the same organ piece will require a different touch and tempo when performed on 2 different instruments situated in different buildings. This is not so much true with piano pieces. Organists therefore are faced with adjusting their playing more so than a pianist. If you ask a pianist about it they will quickly disagree with this premise because they're looking at it from their own viewpoint, but, if you're looking at it strictly from an organist's point of view, this point becomes quite evident. The different varieties of organ pedals alone is proof of that [See blog, Diminutive Pedalboard].
When moving from the organ to a synthesizing keyboard or, let's say, to a digital stage piano with weighted hammer action, the situation is exactly the same as when coming to an acoustic piano. Wonderful as these new state-of-the-art instruments are, it still takes some experimentation with it to get the sound you want as an organist and the phrasing you need (and, because it's a keyboard and not a pipe organ, for all your time spent learning different technique, you get to where you haven't even touched the pedals). When you're moving from the piano back to the organ you notice other things: every note you happen to bump, nudge, or smear will be heard at full volume on the manuals of an organ. The exclusion of the piano's sustain pedal and sostenuto pedal is one of the first things you miss. Since there's no pedal to cover gaps between notes, there's a different technique, using finger substitutions, to organ legato. Rolling your hands over the keys as opposed to attacking them pianistically can be a real problem at first that may take considerable practice. Also, when learning the Bach Inventions or other contrapuntal pieces, the techniques of finger substitution assist the absolute necessity required of such music, and, for this reason, skilled pianists often cannot easily play Bach on the piano. The techniques required of playing the piano and harpsichord (the concert keyboard instrument Bach knew and used in public) are also completely different, the harpsichord being much nearer to the technique required for organ playing.
One of the things normally learned in basic instrument lessons, such as piano, is the ability to read music, which is probably why most proponents of piano first will tell you that piano is necessary before studying organ: to learn how to read what's on the page, play evenly, and get the familiarity with the keyboard layout. In the long run it's probably best not to put a number on the amount of years or whatever that you have to have before you can touch the hallowed keys of the organ. We're on solid ground if our goal is simply to have the above mentioned abilities: be able to read music at the keys, play everything evenly, and know where all of the keys are in order to navigate the keyboard. The rest generally comes with experience.
By the way, if you're an organist presiding at an important instrument, and let's say a definite talent who already plays major organ pieces well has sought you out and is begging you to teach them the organ, and you agree to take them on as a student under the condition that they work a little more at the piano to bring their sight reading up to speed [See blog posting "Sight Reading"], you should NEVER, EVER, tell them you want them to first learn all 30 Bach Inventions and then delegate the teaching of all 30 of them on the piano to one of your organ students. Talk about a thumb in the eye. It will now be up to a third party, a disinterested intermediary, to decide and report back to you how soon that new, eager talent is ready to proceed, with all feedback information filtered to you through that intermediary, and a financial incentive in place for that intermediary to stretch that time to suit himself. But, what's worse, and more importantly, the interest of that new, eager talent will be in danger of being ground to powder. All over a piano. It would be far better to start them at the organ with you, teach them about the principles of sight reading, direct them to suitable materials, and use the Inventions as assigned work with the stipulation that they be practiced at the piano, if that's what they need (maybe spacing organ lessons a little further apart to give them time to work at it).
The mind of that potential student, any student, is their greatest investment, and it's more fragile than most teachers can ever begin to realize. How irresponsible it would be, as an elegibility requirement to work with you, to tell a talented potential student that they have to start at the bottom on a different instrument, then expect them, in effect, to construct the Taj Mahal out of toothpicks under the disinterested supervision of one of your acolytes! Taking a promising young talent, who at the audition demonstrated proficiency with major repertoire on a level of a senior majoring in organ in college, back to keyboard kindergarten before they can even think of studying privately with you at the organ, is a move guaranteed to destroy their interest. After two of these so-called piano "lessons" with your acolyte focused solely upon a 5 finger exercise on middle C for right hand only, that potential student of yours won't see any point in continuing along these lines, serving out this "sentence" you've imposed until icicles are hanging in a very hot place. You'll send them packing with their head full of doubts about continuing with the organ at all [See blog, What About Bench Position]. If you think something like this can't ever happen, that the possibility of this is just far too remote, think again. It actually happened exactly as described a half century ago to a young organist I knew back then.
This piano keyboard, as everyone knows, is 88 keys long spanning a little over 7 octaves. The organ keyboards, or manuals, in America have a standard compass of 61 notes, or 5 octaves, and perhaps a little less in other countries (instead of running up to C6 the manuals might end at A5 or even G5). Historical copies of these instruments are generally built the same way because the literature written for these instruments did not require these extreme high notes. If we measure the distance from bottom C1 to high C6 on an organ manual, we'll come up with a figure of around 33 inches. But on the piano, when we measure the distance across five octaves of keys, it's larger, around 33.5 inches. This means that when we come to the organ there's a difference, it isn't much to measure, but we notice that difference when we try to play or switch from one instrument to the other.