|Celestes are mesmerizing, transformational and often rapturous. It seems difficult to make a truly poor one. Where cornets, trumpets and principals are excruciating, even the crunchiest neo-classical Salizional and Schwebung will be somehow tolerable. In this respect, celestes have often been regarded as the instruments public relations agent. The vernacular of organ beauty complexity of principal choruses, sophistication of cornets, the acquired taste of initially quirky solo reed tone takes time to learn and appreciate. Against this backdrop, celestes have powers of instant access, often speaking a language of common attraction, other-worldliness. Note how synthesizer-makers have adopted the celeste effect so freely, creating mellifluous quasar tones suggesting the celestial.
Celeste effects also reveal the magical possibilities of organ pipes disagreeing with one another. Rather than becoming twice as loud when the celeste is drawn, the tone becomes three-dimensional. Even the most beautiful organ tones are static: with a celeste, there is at once motion and direction imparted to formerly stationary sound. Mass and warmth was how G. Donald Harrison phrased it; others have referred to the mysterious sense of motion or depth of field a celeste can create. Additionally, undulating registers have a beguiling way of transforming their respective tonalities: principals becomes stringy; strings turn reedy, horn-like or, in some cases, fluty (when the color of the beats emphasizes the pipes fundamental rather than harmonic development). Dull-toned tapered registers start to glow with quiet brilliance, while full-toned flutes take on laser sheen. The out-of-tuneness, and the uncanny way pipes talk to (and sometimes fight with) each other, combine to bring less prominent tonal qualities to the forefront.
When we consider celestes today, we think generally of strings. However, the first celestes existed well prior to the development of organ strings, and are to be found in 16th-century Italian instruments as principals. The Voce umana is a principal celeste, commencing at tenor f, creating a heavenly effect reserved for the music of the Elevation. Given the fact that 8-foot Principal stops were sometimes duplicated in larger Italian instruments, it is easy to imagine that the first celeste was simply an out of tune second principal (perhaps a disagreement between interior and façade stops?).
At the same time on the Iberian Peninsula, similar stops can be found. Manuel Rosales writes, A further adaptation by the Spaniards, and later the Mexicans, took the form of a treble pair of open wooden flutes, called Flauta travesera. Tuned to a slow undulation rate, these stops produce a highly beautiful, even mesmerizing effect. The same stop tuned quickly can be found on other instruments under the name Violines.
The celeste effect also became known in Germany, where organs of 18th- and 19th-century German explored the celeste effect most commonly through a stop called Unda maris. Compass varied from low CC to tenor A. Unlike the prominent tone of the Voce umana, the Unda Maris was an echo-type voice for special moments: think of certain of the quietest passages in the Reubke Sonata, for example.
The first recognizably modern development of celeste tone was Cavaillé-Colls 1846 introduction of the Voix céleste on the unenclosed Positif at the Church of the Madeleine in Paris. In subsequent instruments, Cavaillé-Coll made the Récit the celestes customary home, where it could gain powers of dynamic nuance. By the end of the 19th century, stock model Cavaillé-Colls with as few as nine stops would still contain a Voix céleste. Three-manual organs in the 40-register size often contained a second undulant, a broader tone called Unda maris and placed in the Grand-Orgue or Positif. Cavaillé-Coll built two organs with three celestes each. The largest of three organs built for the Baron LÉppe, at Biarritz (an organ that, in rebuilt form, now resides in the Basilica of Sacré-Cur, Paris) had three celestes of identical scale. The famous organ at Saint Ouen in Rouen, however, had three contrasting celeste registers: the usual Récit Voix céleste; the broader Positif Unda maris (equally successful with either Montre or Gambe); and an unusual Voix éolienne, a stopped metal chimney flute slightly larger in scale than its non-chimneyed mate, the Cor de nuit.
Contemporary English taste seems to have viewed the celeste with reluctance. Only by the 1860s did Father Willis introduce celeste tone, and, like Cavaillé-Coll, he placed it first on unenclosed Choir organs, a Vox Angelica of muted string character. Eventually such voices were found more habitually in the Swell, to become a staple item of that department ever since. T.C. Lewis followed the Cavaillé-Coll model of introducing real string celestes in the Swell, and as early as 1869 was proposing grand organs with two celestes. Unlike the French Unda maris, however, Lewis second celeste was called Vox Angelica, of dulciana tone (such as in the Solo at Southwark Cathedral).
Unlike the brass bridge, or frein harmonique used by Cavaillé-Coll to stabilize speech in strings, Lewis soldered half-round metal bars to the ears of his string pipes. This intense and colorful string voicing paved the way for further developments by such voicers as William Thynne, John Whitely, Robert Hope-Jones and James Nuttall. But despite bringing strings and their celestes to a high degree of refinement, the English organ into the 20th century continued to view celestes as highly specialized. Finding more than three celestes on the same instrument is as rare as one that extends to low C. The Lewis tradition of real Swell strings faded out in preference for the Willis concept Vox Angelica concept. For the Solo, Arthur Harrison specialized in Hope-Jonesstyle Violes dorchestre, voiced to reedy perfection. And yet those violes were viewed first as a family, to which the celeste was an added feature, not the primary attraction. One can note, for example, in the Solo at Kings College Cambridge (Harrison & Harrison, 1936) the choir of strings 16-8-4-Cornet without celeste. Only the largest organs of Henry Willis III went further: both Liverpool and Westminster Cathedral had three celestes each. At Liverpool, the typical Swell Vox Angelica was complemented by biting-type violes in the Solo as part of a comprehensive family 16-8-8-8-4-2-III; and a gentle, open wood flute Unda maris to undulate with the Choir Melodia. At Westminster, in addition to the usual Swell celeste, the Choir contained a haunting Cor de Nuit and Celeste (perhaps looking to Rouen for an antecedent, perhaps at the suggestion of Willis friend Marcel Dupré?) and Solo strings rather broader than the taste of the times more magnolia, less steel.
In America, the celeste remained almost entirely unexplored until the 20th century. Up until 1895, the largest American organs had endless varieties of unison-pitched tone, but only the rare celeste. This is probably the result of an organ culture largely informed, at that time, by British and Germanic ideas. In this regard George Ashdown Audsley must be cited as an exponent of an ideal rooted in those cultures. Although Audsley argued tirelessly for string stops, and introduced the worlds first string organ at the Louisiana Purchase Exposition organ of 1904 (built by the Los Angeles Art Organ Company, later the nucleus of the Wanamaker Grand Court Organ), Audsley thought little of the celeste:
...it produces a peculiar tremulous effect, which one may safely pronounce to be a gross libel on the celestial voice ... the Voix céleste was introduced by the French organ builders, and is quite in accord with the light musical taste of their nation. It is very seldom one hears a Voix céleste that is agreeable to a musical ear: the one in Cavaillé-Coll's Organ in the Albert Hall, at Sheffield, which one might reasonably expect to be good, is unsatisfactory.
Despite initial reluctance, once the celeste concept was embraced, American builders delighted in indulging their inventiveness. The speech stabilizer, which had known many shapes and styles in the 19th century, adopted its enduring form: a wood dowel attached permanently to the ears. Celestes were sometimes provided in threes: flat, prime and sharp, or prime, sharp and double-sharp. Entire divisions were devoted to strings and celestes, the most famous being the 88-rank department in the Wanamaker Grand Court Organ. Although seemingly every form was tried, certain types enjoyed greater popularity. For example, the open wood flute celeste gained an early prominence, thanks to the Austin and Steere companies. Aeolian and Austin took Cavaillé-Colls trio practice (having the Unda maris mate to both Montre and Gambe) one step further, by scaling and balancing a celeste halfway in between a prominent string and an echo string, providing two effects from one celeste register.
In the field of celeste development, Ernest Skinners work set a recognized standard. His early organs contained the usual string celeste, as well as the echo-type known as Dulciana and Unda maris. In 1911, Skinner introduced a new commanding tone. He took the Gross Gamba he had known in the organs of his mentor George Hutchings a slightly reverse-tapered (flared) string with wide slots voiced it with greater assertiveness, and mated it to a celeste, creating a warm wash of tone. At the same time he introduced a very slender two-rank string celeste (one with long feet, to avoid sympathy). Called Dulcet, this stop was in principle not unlike the violes dorchestre of Hope-Jones or Arthur Harrison, but voiced much more quietly: a mild, silvery sheen rather than any sort of intense or biting tone.
Within the next decade, Skinner produced two echo-type tapered registers of enduring popularity. The Flauto Dolce and Flute Celeste, moderately-scaled tapered flutes with narrow mouths and very delicate tone; some were made of common metal, others of spotted; some were voiced with high mouths and very dull tone, others with lower, arched mouths for more edge. Although the difference in voicing was perhaps not apparent with one rank playing alone, the delicate edge tone was drawn out with both ranks together. The Kleine Erzähler was customarily a two-rank stop of sharply tapered gemshorns voiced quiet but bright, with an octave partial equal in prominence to the fundamental tone. The prominent octave heightened the celeste beating, lending intense animation at a very delicate power.
Skinner even went so far as to provide independent 4-foot Unda Maris stops; their union with the Flute Celeste he called the most beautiful sound in music. While this may be taking the point a bit far, celeste tone has fascinated ears ever since it was devised. Are there further avenues as yet unexplored?
 This article was inspired by one of similar topic written by Manuel Rosales in 1994 and published in the Journal of American Organbuilding (the periodical of the American Institute of Organbuilders) in 1995. Information on pre-Cavaillé-Coll historical celeste information has come directly from the Rosales piece, as well as the Audsley quotation. Other information is from the authors own research and inspection.
 George Ashdown Audsley, The Art of Organ-Building (New York: Dodd, Mead & Co., 1905) p. 572.