The explanation of the terms listed below refer to their usage in the field of Mechanical Music. Many of the descriptions are from the book The Golden Age of Automatic Musical Instruments by MBSI member Arthur A. Reblitz, published by the Mechanical Music Press, Woodsville, New Hampshire; copyright 2001. They are used here with permission of the author and publisher. Permission is granted for writers to use a limited number of brief excerpts provided credit is given to the MBSI web site, the title of the original work and the author. Written permission is required for all other uses. German nouns and words that are also names of places are capitalized.

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oboe pipe: Brightly-voiced reed pipe with a conical metal resonator. Used as a solo rank in certain large orchestrions or as a solo and ensemble stop in pipe organs.

octave: 1. A musical interval of eight notes. Every note has exactly double the number of vibrations per second of its corresponding note an octave lower and half the vibrations of its corresponding note an octave higher. 2. Term popularly used to describe thirteen equally-tuned half steps including the notes at each end (i.e., C to C, the twelve-toned equal temperament scale into which the octave is divided on the piano and in most pipe ranks). Sometimes called the chromatic scale. In original catalogs (e.g., Operators Piano Co. description of Coinola percussion) and in popular usage today a "two octave" set of xylophone bars would mean a 24-note chromatic set, for example. As noted, the 13-step terminology is also often used, especially in describing pipe ranks. 3. A 4' pipe organ rank of flute or diapason tone. For example, Welte identified the 4' flute rank in many orchestrions the "octave."

octave coupler: See coupler.

orchestra bells 1: Bar-type bells (See bells). 2. In a theatre organ, bar-type bells played with a reiterating or repeating action. (When the same bells are played with a single-stroke action they are called glockenspiel in organ terminology.)

orchestra box: Cylinder music box with added effects, usually saucer bells, a small drum, a wood block or castanet, and a reed organ section. Most were made in Switzerland. Mainly popular c. 1880-1895.

orchestra piano: Keyboard-style orchestrion.

orchestral flute pipe: Open wood or metal pipe rank imitative of the orchestral instrument.

orchestrion: Self-contained automatic musical instrument, esp. a large one, equipped with several different instruments in imitation of an orchestra. Usually contains some percussion effects (e.g., drums, cymbal, triangle, etc.). Main types include: 1. Barrel orchestrion: with piano and/or pipes and percussion. Made for indoor use. Popular during the 19th century. 2. Keyboard piano orchestrion: built around an upright piano; with one or more chromatically-scaled extra instruments (e.g., a rank of violin or flute pipes, a xylophone, a set of bells) and with percussion effects. Paper-roll operated. Popular during the early 20th century. 3. Large keyboardless piano orchestrion: contains a piano, several (usually) ranks of pipes, and many other effects, some of which are arranged to play solo melodies. Paper-roll operated. Popular during the early 20th century. 4. Small cabinet-style orchestrion: small cabinet, usually smaller than an upright piano, containing an abbreviated-scale piano, one or more chromatically-tuned extra instruments, and percussion effects. Popular during the 1920s, especially in America (e.g., Seeburg KT, KT Special, etc.). * Synonyms for types 2-4: automatic orchestra, orchestra piano. Other uses of the orchestrion term (instruments which were designated as orchestrions by the original manufacturers, but which collectors today consider as part of other series) include the following: 5. Disc-operated piano of limited scale, sometimes with percussion effects (e.g., disc pianos made by Lochmann, Polyphon, and Symphonion). 6. Large disc music box, usually with 10 or 12 bells. 7. Mechanical (not pneumatic) piano of limited scale, plus percussion effects. Operated by a heavy manila paper roll (e.g., Regina Sublima Piano and related Polyphon products). 8. Barrel piano with limited percussion effects. 9. Mechanical zither or dulcimer (e.g., the so-called Piano Orchestrion, also sold as the Piano Melodico). 10. Paper-roll organette (e.g., Orchestrion Harmonette). Instruments listed from 5 through 10 are not considered to be orchestrions by collectors today. The term orchestrion was applied to many other non-orchestrion instruments over the years.

organ: Generally, an instrument which produces music by means of tuned pipes or reeds. Among automatic musical instruments the following main types are found: 1. Organette: small hand-cranked instrument which plays tuned reeds, or rarely, pipes. 2. Player reed organ: large instrument, usually equipped with a keyboard, which plays tuned reeds. 3. Player pipe organ: large pipe organ, usually equipped with one or more keyboards or manuals, designed for providing music in a church, theatre, or residence. Usually not self-contained, but built in as part of a building. With paper-roll player built into the console or into a separate cabinet. 4. Portable hand-cranked barrel5. Band organ or fairground organ with loudly-voiced pipes and ornate (usually) front. 6. Street organ or pierement: loudly-voiced instrument mainly used in the streets of Holland. 7. Dance organ: not as loud as a fairground organ, usually with ornate facade and of very large size, used in dance halls, especially in Belgium and Holland. 8. Calliope: with a limited scale of flue pipes, played with extremely high wind pressure. 9. Serinette: hand-cranked softly-voiced scale of flute pipes; a popular parlor instrument of the 18th and 19th centuries. 10. Any attachment consisting of one or more ranks of pipes or sets of reeds attached to another instrument. * Dutch, German: Orgel. * French: orgue.

organ grinder: . One who grinds, or cranks, a barrel organ.

organette: Small hand-cranked (usually) reed organ, without keyboard. * Synonyms (used circa 1880-1900, not used by collectors today except to describe specific instruments): organetta, organina, orguinette, and other terms intended to designate "little organ."

organocleide: . Sometimes called mandoline basse, because the rapidly repeating notes of the "mandoline" format are extended into the bass section of the comb of a musical box to give sustained low tones, and the overall tonal scale of the program is generally pitched an octave lower to take advantage of this feature.

overture box: A cylinder musical box with cylinders 3" or larger in diameter. Very finely made and pre-1880, containing overtures of operatic selections. In some boxes one air was pinned to play in two revolutions of the cylinder. Most played only two, three or four airs.