Rodgers Trilogy - Three-Manual Console Design; The Great Organ Division; The Swell Organ Division

6
THE THREE- MANUAL CONSOLE
As the art of organbuilding has evolved over the centuries, certain features of the
instrument have become more or less standard as organists, by a process of elim-
ination, gradually have culled out "innovations" that served no real practical function
and merely got in the way. It is thus that tradition has given us the three-manual
organ, and most organ literature has been written for three 61-note keyboards and
a 32-note pedalboard. You have probably noticed that nearly all music written for
the organ contains registration notes for Swell, Great, Choir and Pedal. Adapting
these pieces to the two-manual organ is cumbersome at best, often involving rapid
registration changes and difficult "cross-hand" techniques, an unwieldy compromise
of the composer's intent. In two-manual organs the missing tonal division, if it is
supplied at all, must be distributed somewhere among the stops of the two manuals.
This, of course, is a compromise sometimes made in the name of economy.
Three manuals of 61 notes each and a full 32-note pedalboard give the organist all
the necessary flexibility to interpret organ music the way the composer intended.
In addition, the various tone colors are conveniently available, distributed into di-
visions according to their traditional function in the organ. It may be well, at this
point, to give a short description of the tonal "palette" and function of the various
divisions.
THE GREAT ORGAN -- Center Keyboard
This division is the backbone and main substance of the organ. It is character-
ized by the unique Diapason sound, available at various pitches. This Diapason
Chorus, backed up by a chorus of softer Flutes and crowned by the Mixture,
constitutes the principal support to congregational singing in the church. All
of the other divisions of the organ relate in some way to the Great Organ. An
example is the Swell to Great coupler, to make the Swell voices playable on the
Great manual.
THE SWELL ORGAN -- Top Keyboard
This division contains the more romantic and imitative sounds. There is the
Geigen Diapason Chorus, somewhat less assertive than the Great Diapason
Chorus, and derived from a tone source independent of the Great Diapasons.
There is a quiet String Chorus for soft ensemble playing, and a Flute Chorus
of a different harmonic structure than the Great or Choir Flutes. In the 32- B,
the Strings and Flutes have celestes provided for them, adding warmth and
depth to this division. The Reeds of this manual consist of an imitative Oboe,
used in a solo capacity, and a Chorus Trumpet, used as an ensemble builder
in the full organ. The Swell is named for its being an expressive division,
having the ability to "swell" in volume as the expression pedal is opened. On
the 32-B, this manual is further separated from the other two manuals by
having its own expression, independent of the others.