Zweiklang: Die Musik der Übenden
Two-Tone: Rehearsers' Music
Permanent installation in public space
located at Jakob-Welder-Weg 28, 55128 Mainz, Germany
Soft- and Hardware construction: Sukandar Kartadinata
Organ builder: Orgelbau Stüber Berlin

images / text / movie

"Zweiklang" is a permanent installation in public space situated at the open courtyard of the School of Music of the Johannes Gutenberg University, Mainz. The work is permanently accessible. The central element of the "Zweiklang" is a computer controlled acoustic music machine, similar to a large barrel organ. It comments and quotes the environment of the School of Music. On its abstract level "Zweiklang" can be looked at as an ironic attempt to a "sonification of music"-music. Combing ideas of music with reflections on the history of revolution the installation mocks upon the unlikeliness of the individual to fall for progressive approaches by spending the time with rehearsing and practicing within the frameworks of an academic organization. It is an invitation to find a balance between making and thinking about things.

The Structure of Zweiklang


Directed to the courtyard one can observe 24 rehearsal rooms. These rooms are individually equipped with a network system that gathers the general pitch of each single room, inevitably produced by the practicing students. The information is evaluated and the two dominant pitches and their locations are extracted. This information is being transferred to the organ.


Facing the street and confining the courtyard of the music school a large display cabinet presents a large barrel organ. The organ is a equipped with 24 wooden pipes with computer controlled valves. The street side of the instrument appears to be a scaled down model of the schools rehearsal wing, facing the courtyard, sprinkling it with all sorts of sounds during the day. The windows of the chambers are represented by 24 yellow light bulbs. The other side of the instrument bears two paintings and hand carved veneers that refer to the disappearance of sites that had been dedicated to the German scientist, writer and revolutionary Georg Forster. Additionally inlayed aphorisms connect truth, mistake and revolution.

The Music

As the title implies the organ only plays two tones at a time, changing them every 30-40 seconds. The tones are depriving from the most dominant frequency in the rehearsing rooms. As the rooms are quite small and the rooms are without air condition, the courtyard usually is filled with the cacophonic sound of many different kinds of music at the same time. The drone performed by the organ rearranges the unintended music of the students by trying to add a harmonic basis.

The Text:

The four sentences on the courtyard side of the organ say

The perfectionism promotes the Automaton
(paraphrase on Georg Forster)

No revolution without mistakes
(paraphrase on Fidel Castro)

No lie without truth
(paraphrase on Georg Friederich Hegel)

Whatever happens has to happen
(paraphrase on Georg Forster)

The flower Inlays are based on drawings made by Georg Forster on occasion of James Cook's second circumnavigation of the world. The paintings refer to places that have been named after Georg Forster but lost their title over the cause of the German history.

Comissioned by State Rhineland-Palantinate and the Music School of the Johannes-Gutenberg-University Mainz. Special thanks to the support of Klaus Klein, Friederich Neugebauer and Moritz Reinisch.