The Organ, and the Piano

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I recently rehearsed to myself the differences between organ touch and piano touch; that indefinable quality that enables a good performer to make these instruments sound beautiful.  People who are not knowledgeable about the organ and the piano often believe that the techniques of playing the two are essentially the same.  I can't remember why I thought this a good idea, but perhaps I will remember once I get started...

The organ is really several hundred instruments combined, one for each note.  (Actually, so is a piano.)  They're essentially flutes (or trumpets), and there is a large box full of air (the wind-chest), with hoses connected to each pipe.  When the organist presses the key, a switch opens up the air to that pipe, and it sounds.  For a different note, you press a different key, which sends the air to a different pipe.  The longer the pipe, the deeper the sound.  There is a row of pipes, ranging from a pipe roughly 8 feet long for the C below the Bass Clef, to a little 6" pipe two octaves above Middle C.

The organ can supply different tones by switching on different rows of pipes.  Each row is called a rank of pipes, and the organist gets a rank of pipes ready by pulling out a stop.  So once the "trumpet" stop is enabled (i.e., pulled out), if a C is played, the trumpet C will sound.  Obviously, multiple stops can be pulled, and the note on all the corresponding ranks will sound when played.

In addition, organists can make interesting composite tones by combining stops.  You must have heard octave stops (which play an octave higher, along with the stops that play at "ground level"), super-octave stops --playing two octaves above, and so forth.

A useful way of talking about the octaves is to call the standard octave the 8-foot octave.  One octave higher is the 4-foot octave (or 4' octave), an octave still higher is the 2' octave.  For very serious music, organists will couple in sub-octave stops, 16' for instance, which add notes an octave below the usual sound.

There are other, more amazing notes that take some getting used to; for instance, it is possible to add an octave-plus-a-fifth, which could be, depending on the particular tone of the stop, anything from barely noticeable to highly pungent-sounding, and even more amazing stops.

There are basically two main sorts of pipes: flue pipes, which are basically elaborate whistles, like the instrument called a recorder.  Within this type, there are some sub-varieties: "flute" stops, very wide-bored pipes with a strong fundamental note and few harmonics, in many ways similar in sound to ordinary flutes; "diapason" stops, featuring smaller-bored pipes with a characteristic organ sound, and "string" stops, with very narrow pipes, that give a soft, reedy sound thought to be reminiscent of violin tone (to people with strong imaginations).

The other type is reed pipes, or brass pipes.  These are equipped with a reed that gives these stops a trumpet-like quality, or an oboe-like quality.  A reed is a piece of flexible brass, like the things inside a harmonica.  Reed stops are the trumpet-like stops used when an organist wants a very audible, grand sound.  They're rarely used, unless it is necessary to use a loud inner voice contrasted against surrounding flute voices.

Finally, there are composite stops, consisting of two pipes for every note, each tuned slightly differently from the other, which causes beats when they're sounded simultaneously.  The less said about these stops the better (though they are regarded with favor by a large proportion of organists: vox melodia, vox harmonia, vox celestis, vox humana, and other such voxes are used to describe these awkward stops).

The piano is a very different thing.  Each note corresponds to a string (or up to three strings, all tuned in unison), which is struck by a hammer.  In the harpsichord, it used to be a claw that was dragged past a string, plucking it.  Here, it is a hammer, which must then be quickly removed before it interferes with the string.  The history of pianos is partly the history of the ingenious ways that were found to make the hammer bounce off the string right away: the so-called escapement.  So when you press the key ---and keep pressing it--- the hammer has hit the note and fallen away; the feeling that you're still connected to the note is an illusion.  Of course, once you release the key the dampers come down and silence the string, just as you expect.  (One of the cleverest bits of invention in pianos is the ability to play quick repeated notes.  The hammer falls away after the first note, but is kept ready for a subsequent note, just in case it is needed.  Once the key is completely released, the hammer falls all the way down.  It is almost too complicated a Rube Goldberg arrangement for the average person to learn.  In any case, most of us have played a piano, and we know what it feels like.)

[The diagram above shows the so-called double-escapement mechanism invented by Sébastien Erard, and is an annotated version of an image from Wikimedia Commons.]

Here is a video clip of a key hitting a piece of wire in lieu of a string.  [There are small differences that various piano manufacturers have patented, so this clip may not show what's going on inside your piano, for instance.]



When one plays a piano, one knows that the note keeps sounding as long as you keep pressing on it.  But, obviously, you can't be pressing on the string, because that would damp the sound, and you would simply hear a thud.  What you are pressing against, actually, is just the wooden floor of the keyboard.  It is a clever illusion that has been arranged by the piano engineers that keeps us convinced that our fingers have a direct physical connection to the sound.

In both the piano and the organ, once the key has been pressed, it is the instrument that manages the sound, except that we stop the sound by releasing the key.  All the expression an organist can bring to bear on the note has to be packed into two things: when to press, and when to release.  So in organ music, the fine details of rhythm and phrasing have a lot to do with timing, and an organist chooses the moment at which he or she presses each key with great care.

With a piano, however, there are ingenious devices that enable the player to control the sound.  The velocity with which the key is pressed determines the volume of each note, unlike in the organ, where the volume for the entire instrument has to be set by a pedal.  So when a pianist emotes, and hammers on the keys, he really is making a difference in the sound.  (You can emote at an organ keyboard, but it makes no difference; you can only make it louder by opening up a sort of louvre blind that lets more of the sound through.  Or by adding another stop to your mix.  And only part of the ranks are inside the louvre box (the Swell Box); the rest of the organ is sitting right outside, its volume controllable only by shutting off or turning on ranks of pipes.)

It is this design feature which enables the player to actually affect the volume of each note individually that gave the piano its name: Pianoforte, which means soft-loud.  It's predecessor, an instrument called a fortepiano that was invented around 1750, around the time of Bach's death, had a somewhat simpler mechanism (or action), and was a far smaller and lighter instrument than modern concert grand pianos.  Those old fortepianos had wooden frames on which the (bronze, probably) strings were stretched, and the hammers might have been leather (rather than felt, as they are today).  The bigger, more powerful pianos were developed in the 19th century, and already during the time of Beethoven, there were pianos made with heavy cast-steel frames on which multiple strings could be stretched to high tension.  The higher the tension, the longer the string could be, with a proportional gain in volume, enabling the piano to compete with the larger orchestras of Beethoven's time, and so making piano concertos for large forces possible.  Fortepianos were essentially chamber instruments; indeed Mozart's piano concertos were chamber works, even if the audiences might have numbered a couple of dozen.

Here is Mozart's amazing concerto K 466 in D minor, featuring a fortepiano and a small orchestra.



Here is the same piece played on a modern piano, with modern orchestra:



[Also listen to this version by Gabriella Montero for a less jaunty version. Here is Mitsuko Uchida, a well-known Mozart performer, playing and conducting the same concerto.] 

Modern piano technique, though, is complex; pianists interact with the instrument in complicated ways, and they can convince themselves that caressing the keys in particular ways enables smoother, or more nuanced phrasing of a piece of melody.  The amazing thing is that these techniques actually do influence the phrasing, ultimately via the hammer velocity, the damping, and to a minor degree, even the escapement.  In addition, because of the high tension of the strings, and because the pedals can keep all the dampers off if desired, many amazing effects are possible, via sympathetic vibrations.  A sympathetic vibration is when a second string begins to vibrate, urged by the vibration of a related string; an octave, or some other related note.

To make the point perfectly clear: in playing an organ, once the key is pressed, there is absolutely no point in fussing with the key; you cannot influence the tone any further, except by releasing it.  Furthermore, you cannot influence the note by playing the key hard, or soft.  With a piano, too, you really can't do anything to the key to make a difference to the note, except to release it.  But how hard you hit it (the hammer velocity) does indeed affect the volume.  In addition, experienced pianists exert fine shades of control over the hammer velocity, through sheer experience, and through all sorts of mental devices that may even involve imagining features in the piano that do not exist, but ultimately do affect the tone, through the hammer velocity.

[To be continued, with examples!]

Arch

A few of Mozart's Last Masterpieces

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Don't misunderstand me: I do not mean to suggest either that Mozart wrote just a few masterpieces, or that they were all written at the end of his life.  I just want to talk about a few late ones.

The first is the Piano Concerto no. 23 in A major, Köchel 488.  This beautiful piece wafts in, like a soft breeze, and comes to an end like a happy smile, with one of his most modest codas.  (The "coda" is the last several chords and gestures at the end of a work, the blustery ending part which, in a Beethoven symphony, for instance, seems to go on for years...)

Here it is:

Note the opening few notes, the falling third as we describe it, from the fifth note of the scale to the third.  In this particular performance Malcom Bilson plays a fortepiano,  a gentler-voiced precursor to the modern piano, more appropriate to piano and orchestral pieces of this period, especially with a period orchestra, as that of the English Baroque Soloists (John Eliot Gardiner).  Note: this recording has been performed in a transitional style to bridge Baroque practice (the keyboard instrument plays throughout the work, and if it is a featured solo instrument, it is given special prominence during solo passages) and Classical practice (the solo keyboard sounds only during passages when it is explicitly scored for).  The constantly sounding fortepiano gives the music a certain "crunchiness" that might sound peculiar to those not accustomed to it.

This work is not only one of Mozart's most brilliant and beloved creations, but a jewel of all Western Art of all ages.  Though it does not contain an expression of great sorrow, or holy joy, it still manages to capture our ability to find pleasure in ordinary things.  John Eliot Gardiner describes Mozart's music as showing us what it means to be human, and I completely agree with this view.  The slow middle movement is lovely, with even painfully beautiful moments that interrupt its overall tranquility.

The same falling third is the opening figure of another beloved work of Mozart's, namely the immortal Clarinet Concerto in A, Köchel 622.  Equally well known and equally frequently played, the Clarinet Concerto has a wider range of emotions than the Piano Concerto. (Mozart wrote at least 27 piano concertos, but only one clarinet concerto has come down to us.)  The work ends with a definitely bubbly movement, in startling contrast to the problems with health, money and marriage that Mozart was thought to have been experiencing at the time at which the piece was written.  Mr Köchel's catalog is generally in chronological order or composition or publication--I'm not sure which, but we cannot really assume that the Clarinet concerto is as much a later work than the piano concerto as their respective catalog numbers would suggest.


The clarinet concerto too, has a beautiful slow (middle) movement which is simply gorgeous.  It comes out clearly, how much Mozart loved to write these slow movements, though the structure of the faster movements displayed his structural genius in more obvious ways.  In a slow movement it is impossible to hide behind structure, and your melodic inventiveness and your harmonic skill are painfully or happily exposed, as the case may be.  The falling orchestral "chorus" intersperses each solo essay by the clarinet, and Mozart uses poignantly different harmonies for the repeats.

At about the same time, Mozart also wrote his Clarinet Quintet, Köchel 581, for clarinet and string quartet.  This masterpiece (numbered between the other two, for whatever that's worth) features the same opening falling third as the other two works mentioned earlier.  Again, there is no fuss or drama here; it seems a pleasant conversation among friends, written by someone who had nothing to prove, except maybe that it is possible to write a perfectly satisfactory quintet with a clarinet as guest with a string quartet.


The slow movement of this one is every bit as delightful as those of the other two works; maybe even more lovely.  The intimacy possible with a string quartet is hard to compare with anything else. The phrases seem almost vocal, speech-like, earnest, ardent, eager, conversational.  Listen to the commentary by the string quartet to the opening statement of the clarinet!  Such perfect agreement!  The remaining two movements are jolly to the point of rowdiness, but that was Mozart all over.  Part of the wonder of the man was how such buffoonery and such ineffable elegance could reside within the same person.

These are among the greatest compositions within classical music of the past four centuries, but it is almost impossible to make a list of The Great Compositions of Mozart.  If you like these, there are many, many more, even if you want to give time for only the very best: the last five symphonies, the last five piano concertos, all the string quartets, the operas (most definitely Don Giovanni, The Marriage of Figaro, The Magic Flute, Cosi Fan Tutte), the masses, especially the Great Mass in C minor and the Requiem in D minor, the piano sonatas (especially K310, K330, my favorites); the five violin concertos, The Concerto for Flute and Harp K 299, the Gran Partita, K361, The Sinfonia Concertante for Violin and Viola K 364, and The Sinfonia Concertante for Four Winds K 287b.

[Note: the fact of the two opening notes being the same for the three works featured in this post should not be given any special significance; I merely mention it as a curiosity.  The opening themes of compositions of this period were constructed from arpeggios and scales, and it is easy to see how this particular choice of a germ of a theme would appeal to Mozart.]

Archimedes