Gerhard Lang and composer Martin Kürschner

The Ludwigsturm was built in 1882 on the Ludwigshöhe in Darmstadt near Frankfurt am Main. This lookout tower represents a special type of architecture that has a threefold function: to provide a pleasant viewpoint, a platform for oberservation and a means of surveillance. Inside the Ludwigsturm a winding staircase leads visitors to a 28-meter high viewing platform that opens onto an impressive view of the Rhine Main region. As the visitor ascends, windows on the staircase offer views of Darmstadt, of Frankfurt in the distance, and of the mountains of the Taunus and the Palatinate on the horizon. Within this context Gerhard Lang and Martin Kürschner developed a work on spatial perception and long-distance view.

The work Blauton consisted of two minimal interventions, one by Lang and one by Kürschner. Both used elements related to the outside of the tower to change the perception of its interior. Gerhard Lang's intervention related to the windows, which he covered from the outside with ultramarine blue, translucent perspex. Blue, implying distance, replaced the distance views – rendering Darmstadt, Frankfurt and the horizon invisible.

The strength and position of the sun had an impact on the spectrum of the blue. Transposed into the acoustic domain, this formed the basis for Martin Kürschner's new musical composition. A further element underpinning the composition was the poem* chiseled in the sandstone above the entrance to the tower. Kürschner processed its phonetic material into a sound strip in which the semantic content was transformed into a multilayered "language –sound-continuum". The composition, rising from the vaulted cellar to the staircase, like the blue light, filled the entire space. Visitors experienced the space as a resonator for sound evolving from the very foundations.

These subtle interventions, made in a situation familiar to the citizens of Darmstadt, transformed the experience of the tower's interior without touching it physically. The interplay of the two interventions – the light from the blue perspex and the sound of the composition, made visible and audible the site as a space of colour and sound. By moving certain qualities of the interior space into the centre of the visitor's attention in an abstract form, the two interventions redefined the way in which that space was perceived.

The shift of the visitor's attention inside the tower also changed his/her perception of the space outside the tower; for example the view from the top of the tower. To walk up to the viewing platform, the visitor first opened a blue skylight door and so ascended through the colour. The Rhine-Main region had not altered but at this moment perception of it did.
C. N.

* The poem praising the height of the tower and honouring the Grand Duke of Hesse and by Rhine was written by Wilhelm Schwab, a councillor of Darmstadt, who financed the building of the tower.