reed organ

American Heritage® Dictionary of the English Language, Fourth Edition

1. n. A harmonium.

Century Dictionary and Cyclopedia

1. n. A musical instrument consisting essentially of one or more graduated sets of small free reeds of metal, which are sounded by streams of air set in motion by a bellows, and controlled from a keyboard like that of the pianoforte. The two principal varieties are the harmonium, which is common in Europe, and the so-called American organ, the chief essential difference between which is that the former is sounded by a compression-bellows driving the air outward through the reeds, and the latter by a suction bellows drawing it inward through them. The tone of the harmonium is usually keener and more nasal than that of the American organ. The apparatus for compressing or exhausting the air, and for distributing the current among the various sets of reeds and among the channels belonging to the various digitals of the keyboard, is not essentially different from that of a pipe-organ, though on a much smaller scale. (See organ.) The bellows, however, is usually operated by means of alternating treadles. The keyboard is exactly similar to that of the pipe-organ or the pianoforte, and has a compass of about four or five octaves. The tone-producing apparatus consists of one or more sets of small brass vibrators or reeds (see illustration); the pitch of the tone depends on the size of their vibratile tongues, and its quality on their proportions and on the character of the resonating cavities with which they are connected. Each set of vibrators constitutes a stop, the use of which is controlled by a stop-knob. The possible variety of qualities is rather limited. The treadles operate feeders, which are connected with a general bellows, so that the current of air may be maintained at a constant tension; but in the harmonium the waste-valve of the bellows may be closed by drawing a stop-knob called the expression-stop, so that the force of the tones may be directly varied by the rapidity of the treadling. In the American organ the force of the tones is varied by a lever, operated by the player's knee, which opens or closes a shutter iu the box inclosing the vibrators. The harmonium some-times has a mechanism called the percussion, providing a little hammer to strike the tongue of each reed as its digital is depressed, thus setting it into vibration very promptly. A tremulant is often introduced, consisting of a revolving fan, by which the current of air is made to oscillate slightly. More than one manual keyboard and a pedal keyboard, with separate stops for each, as in the pipeorgan, occur in large instruments. Occasionally a set of pipes is also added, Various devices for sustaining tones in the bass after the fingers have left the digitals, or for emphasizing the treble, are sometimes introduced, Pianofortes are made with a harmonium attached (sometimes called an æolian attachment). The reed-organ has become one of the commonest of musical instrumeuts. Its popularity rests upon its capacity for concerted music, like the pianoforte and pipe-organ, combined with simplicity, portability, cheapness, and stability of intonation. Artistically regarded, its tone is apt to be either weak and negative or harsh and unsympathetic. A variety of recent invention, the vocalon, has a remarkably powerful and mellow tone.

GNU Webster's 1913

1. n. (Mus.) an organ in which the wind acts on a set of free reeds, as the harmonium, melodeon, concertina, etc.

WordNet 3.0

1. n. a free-reed instrument in which air is forced through the reeds by bellows