R-230, -250, -270
SECTION I
1
DESCRIPTION OF STOPS
PITCH FOOTAGE
The number appearing on each stop along with its name indicates the “pitch” or
“register” of the particular stop. It is characteristic of the organ that notes of different
pitches may be sounded from a single playing key. When this sound corresponds to the
actual pitch of the playing key, the note (or stop) is referred to as being of 8’ pitch;
therefore, when an 8’ stop is selected and Middle C is depressed, the pitch heard will be
Middle C. If it sounds an octave higher, it is called 4’ or octave pitch. If it sounds two
octaves higher, it is called 2’ pitch, while a stop sounding three octaves higher is at 1’
pitch. Likewise, a 16’ stop sounds an octave lower, and a 32’ stop sounds two octaves
lower.
Stops of 16’, 8’, 4’, 2’, and 1’ pitch all have octave relationships; that is, these “even
numbered” stops all sound octaves of whatever key is depressed. Pitches other than
octaves are also used in organ playing. Their footage number always contains a
fraction, and they are referred to as mutations. Among these are the Nasard 2-2/3’ and
Tierce 1-3/5’. Because they introduce unusual pitch relationships with respect to the
fundamental (8’) tone, they are most effective when combined with other stops, and are
used either in solo passages or in small ensembles of flutes (see explanation of Cornet in
Section III).
TONAL FAMILIES
Organ tones divide into two main categories: flues and reeds. In a pipe organ, flue
pipes are those in which the sound is set in motion by wind striking directly on the edge
of the mouth of the pipe. Flues include diapason, principal, flute, and string tones.
Compound stops and hybrid stops are “variations” within these three families.
The term “imitative” means that the organ stop imitates the sound of the corresponding
orchestral instrument; for example, an imitative Viola 8 would be a stop voiced to sound
like an orchestral viola. Below is a brief summary of various organ voices, some or all of
which may be on your particular Allen organ.
Principal Voices
Principal
Diapason
Octave
Superoctave
Quinte
Characteristic organ tone, not imitative of orchestral instruments.
Usually present at many pitch levels, as well as in all divisions. Rich,
warm, and harmonically well developed, these voices form the
backbone of the organ.
