Late mediaeval organ

This 15th century instrument is meant to be able to present the music of the Faenza and Robertsbridge Codex in a respectful way. Also the music of the Buxheimer Orgelbuch can be performed.


For this music we constructed an organ with pipes in chromatically order and different soundcolors. It contains two stops, a 8' and 6'. In old Dutch called a "Doeff" and "positie". When used together one can hear an acoustic 16' like sound which gives us a more fundamental tone.

The compass of the organ is A-c''', 40 notes. A pull down-pedal is added with compass of A-aº. It was made after an original gothic pedal board which is remained in the Organeum museum at Weener Germany. It used to be part of the organ of Westerhusen Germany.



The pipes are made of hammered metal, 98% lead,2% tin. It was cast on sand and has not been planed after being hammered. The scales were made after the writings of Arnout van Zwolle. ( Cerf en Labande 1936). A Pythagorean temperament was used, which also is mentioned by Arnout van Zwolle. Voicing was done according to van Zwolle by using open toes and no nicking, on a wind pressure of about 42 mm.

The winding system is build as "blacksmiths" bellows, which can be detached for transport. A small motor can also be used for making wind. Wind which is pumped by hand, makes the organ sound more relaxed.



Size of the instrument: height 2.70 meter, width 0.90 meter depth 0,50 meter without bellows.
The bellows are about 80 cm long.

Casework is made of Lebanon cedar, the keys are covered with holly and the octave with is 19 cm, about 3 cm wider then normal.

The new build organ is in some way a fantasy instrument, but is based on a careful performed study of old sources, such as treaty and images and organ parts still remaining.


In addition to the 2010 Rumsey organ the organshop got the assignment to reconstruct a "dove-egg" scale stop, based on 11th century treaty. The scale is that of a dove egg which is about 35mm nowadays. The scale stays the same throughout the whole stops range. It turned out to be a very difficult task to voice since the bass is very narrow scaled and the trebble is relatively wide scaled. The pipes are made of 98% lead, 2% tinn and a trace of copper. Pipe material is hammered. Soon it appeared there is no obvious relation between the mouthwidth and the cutup. The bass pipes have very high cutups and the trebble exteem low ones. No knicks are used. Large pipes only started to sound ok when putting ones fingers next to the pipe´s mouth. Because of lack of information about using beards in that time period, we assume that organbuilders were already aware of making them and applied them. The first 7 pipes got medievely shaped beards.
Using the organ shows that the speechdevelopment is more different than we are used to nowadays. It gives new musical inspiration.
Jan Kees Braaksma remarks this stop reveals new insites about playing 14th and 15th century music.The early tabulatures sound lovely and even the 3 vioce worldly music sounds greater and richer then ever before.combination of such instrument and singing will shine a new light upon how to play medievil music.


Source:

Berner orgeltraktat: "De fistulis organicis quomodo fiant" (f 2v-3r)
In: Acta Musicologica 20, 1948, page 13-20

Klaus Jürgen Sachs: "Mensura fistularum" page 100
Eher läßt sich Übereinstimmung sehen zwischen der vielzitierte Angabe aus Cuprum purissimum (Sz 3), die (konstante) Pfeifenweite solle einem »Taubenei« (gerade eben) Platz bieten, und den Kreiszeichnungen aus den Quellen der Schule Wilhelms von Hirsau. Die Durchmesserwerte für das »Taubenei« schwanken zwar nicht unwesentlich, schließen jedoch die in den Abbildungen gegebenen Maße ein.


"Listen to the organ Dove-egg scale stop"(1,52 Mb)


"Link to the website of David Rumsey in Basel"


"Link to the article of Kimberly Marshall in 'The American Organist` "