Celeste English Céleste French Schwebung German

When two pipes are tuned slightly off pitch from each other and speak together, they produce an undulating or shimmering tone, due to the beating effect produced by the result tone of the difference of the two frequencies. For example, if one pipe speaks approximately middle C at 256 hz, and another pipe speaks at 254 hz, a wavering of 2 beats per second will be heard when they speak together. This “beating” results from the interference of the two sound waves, alternately reinforcing each other and cancelling each other out. (This principle is also used by the Resultant, but for a rather different effect.)

The term celeste refers to a rank of pipes detuned slightly so as to produce this effect when combined with a normally tuned rank. It is also used to refer to a compound stop of two or more ranks in which at the ranks are detuned relative to each other. Rarely, a single rank of pipes can be made to produce a celeste all by itself; see Bifara and Ludwigtone.

The name Celeste, which in French means “heavenly” or “celestial”, is occasionally used by itself in a stoplist, but more often it is used as a modifier of some other name (see Variants listed below). On the other hand, the name Schwebung, a German word meaning “beat”, is usually found alone. (It is also used to refer to a tremulant.) While most celeste stops include the word “celeste”, not all of them do.

Audsley defines the name Celeste as indicating a small-scaled sharp celeste of string tone, but in actual usage the name can be used for a celeste of nearly any tone quality.

Types of Celestes

Celestes are usually made from strings, open flutes, or hybrids of strings or flutes, at a wide variety of volumes. Stopped flute celestes are very rare, but have been made from the Quintadena (Quintaphon) and the Zauberflöte (Unda Maris). While diapason hybrids such as the Geigen are often used for celestes, pure Diapasons are almost never used. The only known use of a diapason celeste is the Italian Piffaro or Voce Umana, which is also the earliest known celeste, dating from the 16th century. Sometimes a single-rank celeste is voiced so as to combine with either of two different stops in the same division, such as a flute and a mild string.

Reed celestes are practically unknown except on reed organs. The only known exception is the three-rank Tuba Celeste on the now-extinct Chicago Stadium Barton organ. The “Waldhorn Celeste” in the Ocean Grove Auditorium, New Jersey, USA is a flue, not a reed.

Most celestes are at 8', but 4' celestes are not uncommon. 16' celestes are rare but not unknown. The organ in the John Wanamaker Store, Philadelphia, Pennsylvania, USA has celestes at 5-1/3', 3-1/5', 2-2/3', and 2' pitch.

Tuning

Celestes are tuned to beat at anywhere from 1/2 to about 7 beats per second. (For comparison, the bottom note of a 32' stop has a frequency of about 16 hz.) A single rank celeste may be tuned either sharp or flat of normal. A two-rank celeste may contain one normal rank and one sharp or flat rank, or it may contain one sharp rank and one flat rank. In addition to these combinations, a three-rank celestes may be tuned normal, sharp and very sharp, or normal, flat and very flat. Very large orchestral instruments may contain complex celestes of even more ranks.

String celestes are almost always tuned sharp. A common rule of thumb says that flute celestes are tuned flat, but in practice they are often tuned sharp. In general, sharp celestes are more common that flat celestes. The Unda Maris is almost always tuned flat. Brighter toned celestes are usually tuned to beat faster, duller toned celestes slower.

The tuning of celestes is a complicated business. There are basically two schools of thought: one school, advocated by E. M. Skinner, calls for tuning middle C of the celeste to be one beat per second sharp, then setting a temperament on the celeste rank so that it is in tune with itself. As a result, the celeste will beat twice as fast at each successive higher octave in its range. The other school calls for tuning each note of the celeste to a correponding on-pitch rank, adjusting the beats of each not according to the taste of the tuner or organist. This generally results in a celeste rank that is not in tune with itself, but since a celeste rank is never used alone, this out-of-tuneness does not, by itself, present a problem. Most people favor slower beats in the bass and faster beats in the treble; it has been observed that if the beat rate is the same throughout, the overall effect can sound like a tremulant rather than a celeste.

If a celeste rank is physically located too close to the on-pitch rank with which it sounds, the two ranks can pull each other into tune, ruining the effect of the celeste. The remedy for this is to not place the two ranks too close together. Sometimes the pipes of one rank will be given extra-long feet to raise their mouths several inches higher than the other ranks.

Variants

All of the celeste stops contained in this Encyclopedia are listed below.

Examples

Nearly every organ of any size has at least one celeste, and many very small organs as well. Osiris contains about 120 examples of the unqualified name Celeste. The same source contains 43 examples of Schwebung, all at 8' pitch, and all but one dating from the second half of the 20th century.

Schwebung 8', Manual III; Dom, Bremen, Germany; Sauer 1939.

Bibliography