In order to be able to implement all tones of the 72-step ekmelic tone system on a keyed instrument, Franz Richter Herf developed an electronic fine-step organ which he constructed 1973-74 after his own conception. The organ is suitable for composing, studying, and performing of ekmelic music, furthermore, for the representation of the predecessors of our well-tempered tuning (mediant tunings) and of non-European tone systems, as well as for the research in the field of micro-intervals.
The Ekmelic Organ constitutes the prototype of a novel electronic fine-step organ, regarding the construction as well as the features. Its essential components are:
- 6 sound synthesizers,
- 3 manuals (consisting of the keyboards, the key contacts, and the additional push button switches),
- the sound forming,
- the amplifier (with the reverberation device),
- and the loudspeaker.
Each of the six synthesizers generates 12 tones (sawtooth) in 7 octaves (from C thru b5). The overall tuning of each synthesizer can be modified up to a three-quarter tone by means of a trim-potentiometer. An additional vibrato-generator is connected to the synthesizer. The three keyboards comprise 7 octaves each. At the back end of each key, close above it, there is a push button switch located, in white or black depending on the key. These switches are applied with the fingers by sliding backwards along the keys. Two differently tuned synthesizers each are connected to the key contacts via the push button switches (unipolar toggles). Their positions are indicated visually. By applying the additional switches, it is possible to play two different tones with the same key. The synthesizers are well-tempered tuned in themselves and differ among each other in their overall tuning by a sixth semitone. The middle keyboard is tuned normal (a = 440 hertz), the upper one by a third semitone higher, and the lower one by a third semitone lower. Each tone on each of the three keyboards can be raised by a sixth semitone, by applying the associated push button switch. The original tuning of the key is reset by pushing the switch once again. Thus, the semitone can be sixfold subdivided and there are 72 tones within the octave and 510 tones in total within all three manuals available. Furthermore, the overall tuning of the organ can be raised and adapted to the nowadays usual orchestral tunings. The sound forming consists of 6 stops (clarabell flute, diapason, bassoon, oboe, horn chalumeau, and trumpet) for all three manuals, which also can be registered separately. Since the manuals comprise 7 octaves (like on the piano), all stops are in 8' and no further foot registers are provided. The volume is controlled manually or with the foot (swell-pedal). The loudspeaker is built into an own cabinet.
On the sound forming board, there are located from left to right: the volume control, the group of stop switches, the reverberation control, the toggle for the amplifier, the vibrato switch, 6 rotary knobs for the overall tuning of the 6 synthesizers, and the power switch with the indicator lamp.
Playing the Ekmelic Organ requires a novel playing technique which includes all keys and push buttons on the three manuals. The keyboards are slightly tilted to each other in order to reach easier from one manual to another. Pedals are not provided.
After more than one year of construction, the organ was completed in
. The components came from the company Dr. Rainer
Böhm & Co., Minden; the push button switches were manufactured by
the company Rudolf Schadow KG, Berlin. Helmut Baron and
Georg Eberl, both from Salzburg, deserved well of their assistance
in the completion of the organ.
Thereafter, the organ was demonstrated in public in the ORF Regional Studio Salzburg. A recording for the radio was produced, followed by TV productions in Austria (“Kontrapunkt”, ORF, Salzburg, ) and in Bavaria (“Spielwiese”, ZDF, TV studio Unterföhring Munich, Germany, ).
In , a second Ekmelic Organ was constructed by Ing. Reinhard Hanel for the Mozarteum Academy Salzburg. It has a different construction in some items:
- The three keyboards comprise 6 octaves each (from C thru c4) and there are 438 tones totally available.
- The synthesizers generate sawtooth or square waves.
- Two controls for vibrato speed and intensity, respectively, are located to the right of the top manual.
- A control for the reverberation content is located to the right of the middle manual.