„The horns are industrially standardized products for shipping traffic. Christof Schläger adapted
the horns by alterations in order to be able to use them musically. Now you can play a chromatic
scale on them."
Construction of instruments
One instrument consists of 32 tonal airpressure horns. There are four groups of 16 horns assembled
on a 5 m [=16.4 feet] high lifting tower. In the construction is the electronic and pneumatic
controll unit. The whole instrument will be controlled by a extra notebook. The musician can start
and supervise the composition, which is saved in the notebook.
Controlling the orchestra
In order to play these machines, Schläger initially used an industrial control system by Klöckner Möller,
which is still in use for the regulation of waterworks, railways, and traffic lights. However, this method
of programming proved to be cumbersome, he therefore decided to apply the data transfer protocol MIDI
(musical instrument digital interface) which offered him much more convenient options. However, it is
necessary to interpose a laptop with sequencers, compositional and notation programs between the two.
With MIDI the programming of the operations of motors and magnetic pickups is enabled.
Although the sound machines are then ready for use in performances and in installations, they are not
considered completed, rather they are subject to an ongoing process of modification, a constant fine-tuning
and adjustment of their sound characteristics.
We need a space
The best way is a stage of 80 cm height. A special elevated outstanding place is also
possible. Important is that the audience don't block the sound and the horns can be
seen by other people. It is possible to build up the whole concert in one day. We need
manpower (two strong man) to build up the instruments. It takes 4 hours to build up
the Instruments and three hours to dismantle. A small rain shower don´t disturb the
concert, but we play with more pleasure at dry conditions.
For the computer and other electric, we nee 230 Volt AC power connection (5 ampere is
sufficient). All sounds are pure acoustic, there is no amplification necessary.
We need a compressor
To play the instruments, we need a mobile compressor. This should be a "silent" compressor,
less than 90 dB loudness. The best place for the compressor is 20m away from the stage
Pressure: 7 Bar (100 psi USA/GB)
Intake air volume: ~2000 liter per minute (100 cfm [cubic feet per minute] USA/GB)
Example of a compressor type: for example, Kaeser M50.
The compressor should be rent by the organizer.