Issues discussed at the
Reed Organ List.
The pages linked to below
are a service to
the members of the list,
to show pictures and data
about the instruments discussed.


Estey Style Z and/or O

Estey EPRO Organ

Temperaments project

Cluj Cathedral Rumania




Temperaments project

Temperaments in free reeds

Reed Organ List is a mailing list to bring together those interested and fascinated by instruments based on free reeds.

Reed Organ List is one of many forums, it has however, proven in history to be the "Rolls Royce of lists" on reed organ and harmonium. Many of the members have become 'scholars' over the decades they have been involved with reed organs and harmoniums. Some of them autodidact, some of them academic scholars before they fell in love with free reed instruments.

In december 2008 the issue of temperaments was mentioned in depth on organ related mailing list "Piporg-L", a mailing list focused on pipe organs. Some of the contributors mentioned "reed organs have been a major factor in acceptance of equal temperature" Immediately, others replied that no reed organ ever has been tempered in equal temperament.

Based on a first entry by Robert F. Gellerman, author of 2 major books on reed organs and harmoniums, Frans van der Grijn, dutch webmaster of decided to insert a dedicated page in his web site on this very interesting topic.

Our goal is to build a data collection of free reed instruments in order to find out:

  • did free reed instruments exist tuned in equal temperament
  • what influence had free reed instruments in acceptance of equal temperament in contemporary music.


First entry by Robert Gellerman


Prescott Lap Organ


bass viol maker in Deerfield, NH from 1809 and Concord, NH from 1831; began making lap organs patterned after Bazin's elbow melodeon in 1836, followed by melodeons;
changed the firm name to Abraham Prescott & Son when his son Abraham J. came into the business in 1845. About 1849 the name A. Prescott & Sons was used.

Abraham retired in 1850, and sons Josiah B. and Joseph W. joined the firm which was renamed Prescott and Brothers, and in 1853 Prescott Brothers, located at No. 3, Merchants' Exchange (upstairs) and later at the South end of Main St. near the railroad.
Joseph W. Prescott withdrew from the company in 1853 and went into business for himself as a melodeon maker. Josiah died in 1857 and the youngest brother George D.B. Prescott joined in 1859. The name was changed to Prescott Organ Co. in 1871 and incorporated in 1881.

They began manufacturing pianos in 1886 and in 1887 changed the name to Prescott Piano & Organ Co. When organ production ceased in 1891 the name was changed to Prescott Piano Co. In 1890 the office and factory was located at 71 South Main St. and the sales rooms were at 92 North Main St., Concord.

The factory burned in 1896, and the company went out of business in 1912, ending the corporate life of one of the pioneers of the American reed organ industry.

Serial numbers: 1845 - 515 & 541, 1848 - 1270.

Prescott Lap Organ in full colour


In 1986 Robert F. Gellerman did some research on Lap Organ # 1270 from 1848. These data can be used to determine the temperament of the instrument.

Prescott datasheet


Pitch in history

Original text with translation in Dutch and English

Prof. Dr. Oskar Bie: Das Wesen der Tasteninstrumente, Leipzig, 1910.

Zunächst stand noch lange Zeit die Höhe der gegebenen Töne nicht einmal fest. Zu früherer Zeit gab es enorme Schwankungen. Im Jahre 1822 wurde die Schwingungszahl des eingestrichenen a untersucht und noch gefunden, dass sie im Orchester des Berliner Theaters 437, in der großen Pariser Oper 431, im Théatre Feydeau 428, im Théatre Italien 424 betrug.
Elf Jahre später differierten noch die Schwingungszahlen von fünf untersuchten Pariser Stimmgabeln um ein bedeutendes. Noch stärker in Wien. Scheibler machte im Jahre 1834 den Vorschlag das eingestrichenen a zu 440 Schwingungen anzunehmen, aber er drang nicht ganz durch.
Erst im Jahre 1858 wurde durch die Pariser Akademie der sogenannte Kammerton von 435 Doppelschwingungen in der Sekunde auf das eingestrichenen a festgesetzt, und es scheint, daß er sich jetzt allgemein durchsetzt.

Prof. Dr. Oskar Bie: Das Wesen der Tasteninstrumente, Leipzig, 1910.

De essentie van toetsinstrumenten
Aanvankelijk stond over een lange tijd gezien, de waarde (hoogte) van de tonen niet eens vast.
In vroegere tijden waren er enorme verschillen. In 1822 is het aantal trillingen van een ééngestreepte a onderzocht en werden de volgende toonhoogten geconstateerd: in het orkest van de Berlijnse Theater 437; in de grote Parijse Opera 431; het Theatre Feydeau 428; in Italië Theatre 424.
Elf jaar later, verschilden de trillingsgetallen van vijf Parijs stemvorken nog steeds aanzienlijk.
Sterker nog in Wenen. Scheibler opperde in 1834 het voorstel om de ééngestreepte a vast te leggen op 440 trillingen, maar dat gelukte hem niet.
Pas in 1858 werd door de Parijse Academie van de zogenaamde normaal toon van 435 dubbele trillingen per seconde op de ééngestreepte a vastgesteld, en het lijkt erop dat deze toonhoogte nu over het algemeen gangbaar is.

Prof. Dr. Oskar Bie: Das Wesen der Tasteninstrumente, Leipzig, 1910.

Initially, seen over a long time the value (height) of the pitch was not even a fixed number of vibrations per second. In former times there were huge differences.
In 1822, the number of vibrations of an a1 was reviewed and the pitch observed: in the orchestra of the Berlin Theatre 437; 431 in the great Paris Opera; 428 at the Theatre Feydeau; 424 at the Italy 424 Theatre.
Eleven years later, the rates of vibration of five Parisian tuning forks still differed significantly.
Even more in Vienna. Scheibler in 1834 suggested the proposal to fix the a1 at 440 vibrations, but that did not succeed.
Only in 1858, the Paris Academy of the so-called chamber tone of 435 double vibrations per second on a1 was determined, and it seems that this pitch is now generally prevalent.




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