A comprehensive dictionary of organ stops - Allen Organ Studio of ...

DICTIONARY OF ORGAN STOPS. 10J
ad absurdum. Precisely the same discordant sounds, as are indicated above,
are generated by the harmonics of the chord themselves. But such har-
monics, and the artificial harmonics of good Mixtures, are altogether sub-
servient to the prevailing notes of the chord. And as regards the equal
temperament difficulty, there is the same clashing of harmonics whenever a
minor Triad is sounded.* On this score, no objection can validly be urged
against duly subordinated Mixture tones which does not in some measure,
hit at the whole basis of our musical system. Similarly, it is precisely in
so far as compound stops are intended to corroborate natural harmonics
that they are able to withstand the theoretical academic charges of
sedulously giving rise to consecutive fifths.
At the period when compound stops were at their zenith, there were
various names given to them, each strictly indicating a certain definite
disposition of ranks. Such names were : Sharp Mixture, Acuta, Furniture,
Cymbal ; Quint Mixture, Plein Jeu, Full Mixture ; Sesquialtera ; Grave
Mixture, Quarte, Quarte de Nazard, Rauschquinte, Rauschpfeife ;
Tertian,
Sexte ; Cornet, Mounted Cornet, etc. It would serve no useful purpose
to append the constitution of all these in detail, suffice to say, that those
between the several semi-colons are, more or less, cognate, and that the
more important are described in this work under their own title.
In treating full-toned Mixtures the secret of success lies in keeping the
octave ranks bright, and the quint ranks dull and free from their own
harmonics. Mr. Compton, of Nottingham, has voiced some remarkable
Mixture stops, employing rather large-scaled pipes furnished with mouths
of singularly small width. In this manner he has secured a tone of full
quality, free from too ample harmonic development, yet subdued in power.
It is obvious that Mixture pipes would be too small to be continued
with efficiency right through the compass. " Breaks, " or returns, to a
lower pitch, are, therefore, introduced at such positions in the compass
as shall render the change least perceptible. The abruptness of the
break in the ordinary Mixture is far from pleasant. Preferably, each
rank should break back on a different note. Mr. Compton has
consistently designed his breaks in this manner, and Mr. Casson has
worked on the same plan at the London Organ School, and elsewhere.
The power of the different ranks, as they progress through the gamut,
requires, also, careful regulation. If a low pedal note be depressed, with
the Great or Swell organ up to Mixtures coupled, the balance is not
usually pleasant, generally for the reason that the lowest pipes of the
Twelfth are too obstreperous. Albeit this test is a severe one, and it
* The " Tierce de Picardie " is an attempt to escape one of the most serious of these
dissonances. It is open to question whether the abrupt change of tonality is not a far
worse evil. The final tonic minor Triad has an ineffable potency and transcendentalism
of tone,