The cathedral is home to a main organ and a choir organ. The design of both instruments blends with the décor of the rest of the cathedral. The original design for the exterior of both organs was conceived by Prof. Johannes Schilling and developed in detail in consultation with the organ builder and the cathedral musicians.
The main organ
The basic concept of the exterior design of both organs was designed by Prof. Johannes Schilling and detailed in consultation with the organ builder and the cathedral musicians. When designing the main organ - using a large percentage of the existing pipe material and also the windchests - a major challenge was the design of the Rückpositiv. This ‘small’ organ at the player's back is not really small in a ‘full-grown’ cathedral organ, but rather a ‘counter organ’ with its external dimensions of 3.70 m high, 2.90 m wide and 1.60 m deep, weighing over two tonnes.
By lengthening the façade pipes of the Rückpositiv, it was possible to integrate them visually into the main case. The result is a staggered arrangement of pipe fields set one behind the other, which behave like theatre backdrops and allow the observer a different view of the instrument from every vantage point. Any form of visible framework was also deliberately omitted from the main organ: The silver glow of the pipes rests on the anthracite-coloured substructure, making the organ appear to almost float despite its enormous size of 8 m high and more than 6 m wide, with a visible depth of 4 m.
The choir organ
The design of the choir organ incorporates elements of its surroundings. The substructure is made of oiled oak, as is the seating in the cathedral. Its shape follows the rising steps of the choir platform in the west. Overall, the organ is built as a cube that does not touch the walls of the chapel in which the instrument is located at any point. The two sides visible to the visitor are designed as a façade with pewter pipes, while the rear sides are made of oak using the frame-filling technique. The stabilising frame of the front pipes is not visible; a structure is only created by the course of the labia. These follow the staircase on the west side and have an almost ‘classically’ symmetrical appearance on the south side. Only a thin steel plate forms the upper end of the organ so that the pipes can ‘grow’ upwards freely.
The main organ
© Manfred Zimmermann, EUROMEDIAHOUSE
The choir organ
© Manfred Zimmermann, EUROMEDIAHOUSE
Organs are visually connected
A visual connection between the main organ and the choir organ is created via the new choir platform in the cathedral: The treads of the platform steps take up the colour of the substructure of the main organ, the steps of the platform are made of the same wood as the substructure of the choir organ.