The monumental dimensions of the majestic Konstantin-Basilika invite thinking in appropriately grand dimensions — tonally, visually, and technically. The Dresden architect Dr. Klaus-Jürgen Schöler designed the basic concept: three independent, approximately equally-sized organ towers (outer dimensions 2.9 x 4.9 x 10.4 m), placed into the three window niches beneath the glass segments, each with only one row of monumental pipes of 32’ and 16’ open diapason stops. The division into three towers allowed the structure of the south wall to continue spatially into the room. Prof. Carlo Weber from Stuttgart (Auer & Weber) designed the surrounding platform with its spiral staircase made of blackened steel, the final form of the oak organ towers, and their anthracite coloring with matte façade pipes.
A particularly daring concept was the suspension of the organ without cables or supports: inside, steel cages stiffen the tower constructions like a corset; these stand on the benches of the window niches and are anchored at the top into the south wall (from the 19th century), which carries the approximately 50 tons. The planning and construction process, which lasted a good eight years, was commissioned by the state of Rhineland-Palatinate (LBB Trier, especially Ms. Brigitte Coen), the building´s owner. For the realization, an international organ jury selected the Bautzen workshop Hermann Eule Orgelbau (founded 1872) in 2008, a company that had drawn attention in the recent decades with several significant organ projects (Leipzig, Bodø/Norway, Vaduz/Liechtenstein, Mozarteum Salzburg, Prague, St. Petersburg, Borgentreich, among others). Their 45 employees possessed excellent qualifications to realise an artistically high-quality organ and voicing. The organ was dedicated on the first Sunday of Advent 2014.
The six tonal divisions of the instrument are distributed across the cases: in the central tower, the Great Organ in the middle, above it the Swell (II manual); in the upper section of the left tower, the Récit (III manual); in the upper section of the right tower, the Orchestral (IV manual) and the Solo division (which has no manual of its own, but is freely coupleable to all keyboards); the pedal organ is natural-sharp divided, located in the outer towers, with the Great Pedal organ below and the Small Pedal organ on the middle level. The three manual divisions in the upper part of each tower are enclosed in massive wooden swell boxes. This arrangement enables all divisions to project sound broadly, directly, and unobstructed into the space. The organ divisions are built completely self-supporting on the floors inside the three towers. The internal supporting framework of the organ is made of softwood. The connections between the three towers providing action and electrical systems are embedded in the belt of the surrounding platform. Each organ tower has its own electric blower, while a fourth supplies the high-pressure stops. Four pre-reservoir bellows, eight main reservoir bellows, and two auxiliary bellows supply the organ with wind, differentiated from division to division, and doubly differentiated within the Solo division. The windchests are built as slider chests. The key actions of the Great and Swell are directly mechanical; the divisions in the side towers are mechanical, supported by Barker levers; only the Solo division, the Celesta, the Chimes, and some unit chests are played electrically. The stop action is electric.
The organ has two consoles: the attached main console in the central tower has mechanical key action; the second console, which can be placed in the nave near the organ or near the altar, is played entirely through electric action. Their functional design was deliberately chosen to be identical, with easy-to-handle stop tabs and the Eule organ electronics system. Of the 6,006 pipes, only 58 are visible in the façade. Most pipes are made of high-quality tin-lead alloys; 398, mostly larger ones, are made of wood; and 204 pipes are made of zinc — supporting the tonal character of romantic string sounds. One stop, the Celesta, has 61 steel sound plates; the Chimes are comprised of 25 tubular bells.
The tonal vision is a symphonic, quasi-orchestral organ with an extraordinarily rich and varied timbre and a vast dynamic range that can be multiplied many times over, bringing to life the surging power and fading away, the passion, and the entire emotional world of Romanticism. The starting point was the acoustics of the enormous space of around 60,000 m³, which, despite reverberation lasting up to seven seconds, always remains clear, malleable, and unobtrusive. The tonal character and personality of the Eule organ were decisively shaped by chief voicer Gregor Hieke, who, together with his voicing team and with sensitive intuition for the sound world of Romanticism, crafted it masterfully — not as a historicizing reproduction, but as an Eule organ of our own time. The tonal core was developed from the great Central German Romantic organ tradition, specifically from Friedrich Ladegast, with his arc spanning from the late Baroque of Bach’s era to High Romanticism. It inspired the pleno sounds of the Great and Swell/Oberwerk divisions, the profound supporting basses in the pedal, and the nuanced differentiation of flutes, strings, and solo reed stops. The Récit is inspired by French organ building, such as that of Aristide Cavaillé-Coll — its rich tonal resources with singing flutes, brilliant reed stops, and great dynamic range are among its defining stylistic features. The IV manual Orchestral & Solo combines distinctive characteristics of English and American organ building, which brought orchestral dynamics and color to perfection at the very end of the late-Romantic musical development in the 1920s: the magnificent string chorus, sublime imitations of orchestral instruments, and the sonorous high wind pressure solo voices such as the jubilant Konstantin Flöte, the majestic Tuba Imperialis, and the Principalis Romanus with leathered upper lips, whose names are a reminiscence of the former Roman palace building. Fifteen couplers allow the combination of these tonal divisions up to the full range of the full organ; seventeen octave couplers facilitate multi-dimensional chorus effects. More than two- thirds of all manual stops are enclosed in the three swell boxes — their synchronous opening and closing by means of a lone swell pedal coupler creates an imposing tonal crescendo, which, through the possibilities of registration (for example with the crescendo roller) and coupling, can achieve an almost infinite variety of sound — from the barely audible pianissisimo to a fortissimo that is never blaring, rather grand and majestic.

Jiri Kocourek, Hermann Eule Orgelbau