A Dictionary of Music and Musicians/Solo Organ
SOLO ORGAN, a manual or clavier of an organ having stops associated with it which for the most part are intended for use solo, that is, in single notes as opposed to chords. The solo organ is generally a fourth manual placed above that of the swell; but it occasionally supersedes the choir organ, and is then placed below the 'Great' manual. The stops in a solo organ are most frequently (1) Flutes of 8 ft. and 4 ft.; (2) A stop of clarinet-tone; (3) a stop of oboe-tone (orchestral oboe); (4) Reeds of 8 ft. and 4 ft. of trumpet-tone (tromba, tuba, etc.). Larger solo organs contain also stops imitative of the violin, horn, piccolo, and other instruments; perhaps also an open diapason, and, in a few cases, a carillon or glockenspiel. The solo trumpet-stops are most frequently on a heavy pressure of wind, and in order to obtain special brilliancy are sometimes 'harmonic,' as are also the flutes; that is, they have tubes of twice the ordinary length, pierced with a small hole at their half length. Some of the stops of a solo organ are often used in chords, such for instance as flutes and reeds. This is most commonly done by means of a coupler 'Solo to Great,' by which the diapason or flute tones of the solo organ can be used as a valuable reinforcement of the foundation stops of the Great manual; and the tone of the full Great organ can be similarly enriched by coupling the solo reeds. In instruments which contain a Vox humana, that stop is perhaps more often found associated with the Swell-manual than with the Solo-manual; but when placed on the solo organ its pipes are generally shut up in a separate box with Venetian shutters worked by a second swell-pedal. When composition-pedals are made to act upon the Swell, Great, and Choir organs, it is evidently wise to make the combinations they produce proceed as gradually as possible from piano to fortissimo. But this simple principle is not applicable to the combinations or rather selections of solo stops which are made by means of composition-pedals or pistons. The difficulty seems however to be overcome by a method suggested some years ago by the writer of this article; namely, to arrange them in the order in which the instruments are found in a modern full-score. Thus, six combination-pedals would act on the solo-stops in the following system:—
(1) Stops of Flute-tone.
(2) Stops of Oboe-tone.
(3) Stops of Clarinet and Bassoon tones.
(4) Stops of Horn-tone.
(5) Stops of Trumpet and Trombone tones.
(6) Stops of Violin and Viola tones.
This method, which is at once simple and exhaustive, might be indefinitely extended; thus for example, a carillon, drum, or triangle, would be produced by a composition-pedal or piston lying between the trumpet stops and violin stops; and a vox humana would naturally follow after stops of the violin-tone. Smaller solo organs would probably be easily brought under control by combination-pedals or pistons acting on
(1) Flute.
(2) Oboe.
(3) Clarinet.
(4) Trumpet.