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Design and Construction

Specification

The Choir Organ

Design and Construction

The case of the large organ in the west gallery completed in 1739 by Gottfried Sonnholz (III-P/36) originally had a Rückpositiv that was removed in 1868 by the organ builder Friedrich Werner from Graz. Its pipework was integrated into the main case according to new Romantic sound ideals. The only remainders of the former Rückpositiv case were its architrave in front of the balustrade and four angel figures. They had been combined with an ornamental coat of arms of the mother convent St. Lambrecht to close the space in the middle of the protruding and opulently embellished curved halves of the gallery.

This Rückpositiv was once of great significance both for acoustics and appearance: The balance between the voluminous main case and the former Rückpositiv with 11 stops was attained by its prominent position in the loft balustrade. It not only provided excellent distribution of sound, it joined the side wings of the main case and created a satisfying architectural unity of organ and organ loft.

The call for bids for a new organ in the existing historic case called for an organ with three manuals (Great, a second division, Swell), pedal and 50 stops. The church wanted to reuse the Sonnholz main case but made it clear that it did not want a historicized imitation of the past; the new instrument should be of modern design. The second division was to have been installed behind the central 16’ tower of the case in the form of a concealed Oberwerk, where it however would have impaired the sound of the Great below and the Swell behind it because of the crowded space under the vaults. For this reason Mathis also proposed the alternative of reconstructing the former Rückpositiv, an idea that had already been briefly entertained by the Mariazell commission but rejected because of expected opposition from the Austrian Heritage Body. The heated deliberations of all concerned finally resulted in acceptance of this proposal: the Austrian's Heritage Body, represented by Dr. Friedrich Bouvier, agreed to the reconstruction of the Rückpositiv. This decision had repercussions not only for the logical arrangement of pipework, mechanical action and console of the main organ, but for all Mariazell organs as such. It was now possible to abandon the initial requirement of the commission that both of the side organs be electrically attached to the main organ as quasi “positive organs.”

In keeping with the shape of the existing architrave, based on the model of the main case and the fronts of the side organs, the front display of the new Rückpositiv case was reconstructed with five flats and a double curved front. The woodwork of the Rückpositiv, that is the case of spruce and the pipe shades of lime wood were manufactured by Mathis in collaboration with the conservator Carl Maria Stephan from Graz.

In the course of dismantling the electro-pneumatic membrane chest organ in April of 2001 it was possible to the examine the entire historic Sonnholz case construction. All aspects of the construction of the new organ including call for bids, submitting of bids, and awarding of contracts was based on the assumption that the Sonnholz main case from 1737/39 was in its original state. Further examinations by Stephan revealed, however, that the lower case and the parts of the case on the rear organ loft had been significantly modified probably in the course of the changes made by Cäcilia in 1929. The side walls of the passage in the middle of the lower organ case were therefore restored to their original state by reusing original units such as doors and fittings.

The original tin pipes of the 16’ Principal were carefully examined and catalogued. Their walls were unusually thin and their effective length had been halved by tuning-slots. Moreover numerous languids were missing, while others were irreparable and had to be replaced. The front-pipes with natural lengths were narrow-scaled as was typical for Austrian Baroque organs. Their original (higher) pitch had been lowered by roller beards probably in 1912 or 1929. In modern organ scaling practise the original 8’ Principal with a diameter of C = 137.2 mm would be classified as string-scaled while the 16’ Principal with a diameter of its lowest pipe = 251.00 mm today would also be classified as a string stop.

In order to provide the new organ with an optimal bass Hermann Mathis proposed to the commission a new wooden 16’ Principal for the Pedal and to use the original front pipes as both the Great double (c° to d''' complemented by new pipes) and a 16’ Violonbass on the Pedal (C to f').

The layout of the new organ is clear: the pedal soundboards behind the lateral towers of the case stand on either side of the central Great. The Swell fills an archway behind the wind chest of the Great and therefore speaks through the Great. Initially the two voluminous pedal stops, 32’ Untersatz and 16’ Principalbass, were intended to stand in the loft behind the organ in their own casings on either side of the west window. At the request of and according to the design of the responsible basilica architect Wolfgang Feyferlik, however, the almost 18ft. high pipes were placed directly behind the organ, lined up on a simple architrave extending almost 36 feet (11,5 metres).

To achieve optimal acoustics the pipes of the 16’ Principal are situated on both sides of this unusual wind chest, while the pipes of the 32’ Untersatz (C to F sharp as acoustic stop = 10 2/3’) were placed in the center directly in front of the back wall of the organ. The long-wave sound of the two Pedal stops disperse very well through the passages of the organ case and the side galleries of the church.

In respect to the console a decision had to be made whether to allow the organist a view to the nave as Sonnholz originally designed it or whether to connect the console directly with the Rückpositiv case according to Austrian Baroque organ building tradition. The choice was made for a free-standing console placed directly in front of the main case with a view to the organ. This arrangement allows relatively good control of all divisions by the organist. The 180° rotation also has the advantage of allowing the Rückpositiv to be a slim individual unit with easy access to its interior as well as simplifying the mechanical actions of the console.

The design of the console is patterned after the Sonnholz original especially regarding proportions as they are discernible in extant images. The construction was dictated by function: all friezes and frames are supporting elements of the stop action, the keyboards and their action points and of the couplers. In keeping with centuries old tradition quality walnut is used for console, panels, and organ bench. Because of the tanning agent of oak, its use would cause rapid corrosion of the many metal parts of a console. Although the organ builder had intended to retain the natural color of the walnut, the architect had the console painted black in conformity with the color of the main and Rückpositiv cases.

The console has three manuals of 56 keys each. The diatonic keys are of bone and the semitone keys of ebony. The pedal board has 30 keys and is double concave (walnut with ebony covered sharps).

The stop knobs are arranged according to the divisions of the organ; from lower left upwards Pedal and Swell, from lower right upwards Great and Rückpositiv. The order of the manuals is typical of the French symphonic organ: Great (I), Positive (II) and Swell (III).

The Glockenspiel with bells is located in the vault alcove above the Swell box and is played from the first manual keyboard. Further toy-stops are Cimbelstern (not visible from the church nave), Vogelgesang (bird song, four inverted pipes in a small container filled with water), Rossignol (nightingale, a pipe with a mechanism to change its pitch in a fixed pattern), as well as a stop that was named 'Schauer' (a German expression for the rain) in honor of the contracting authority, the Mariazell Superior P. Karl Schauer, OSB. This toy-stop imitates the sound of rain for use in the sort of storm-pieces popular in the 19th century, and is patterned after an historic example in the Hofkirche of Lucerne as a device with iron pebbles that roll in a wooden wheel with metal edges.

The wind supply with two reservoir bellows is as it was in the Sonnholz original on the rear wall inside the organ above the passage to the organ loft. There is one reservoir bellow for Great and Pedal, and the other for Swell and the two pedal stops on the architrave behind the organ. The Rückpositiv has immediately adjacent bellows of its own situated in the gallery's floor.

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The Choir Organ