The kinetic sound sculpture "Sounding Influencer" lets oscillating sine tones sound. These are taken over by the dancer and successively expanded in the degrees of freedom of the movement. The one-dimensional movement of the swinging pendulum is carried into the space and gains variations. The sound experiences a metamorphosis.
The kinetic sound sculpture "Sounding Influencer" emerged from a long sequence of developments of the idea to implement the measured values of heart rate variability in artistic sonifications. In various constellations with dancers and moving loudspeakers, singers and heart detection, the content and form of implementation continued to develop in the four courses Composing for and with Moving Loudspeakers. In the last presentation in June, three dancers with four speakers each should have performed a strict choreography. Unfortunately, this could not take place because of the Corona epidemic.
As soon as it was foreseeable that neither tests nor rehearsals nor performances would be possible, we developed a computer simulation in which the 12 moving loudspeakers with their sound changes could be made audible and enabled the planning of a musical sequence and the choreography. In the simulation, we reduced the speaker movements to swinging back and forth, which gave us the idea of a kinetic sound sculpture in which swinging pendulums move the speakers instead of dancers.
In a first execution, we succeeded in constructing 12 pendulums that can be repeatedly pulled into a horizontal position with the help of motors and released precisely so that they swing freely and swing out.
The sequence of when which pendulums are in motion is determined in the composition, with the swinging out process not being determined, but an algorithmic threshold determining the progression to the next combination. The tone system contains the 12 semitones of equal temperament at 432 hertz.
The movement of the loudspeakers causes an initially strong Doppler effect, but even when a pendulum swings only slightly, a change in sound can be heard very clearly.
A big challenge was the technical realization:
- The pendulum had to swing precisely. An axis had to be developed that would make this possible. In addition, the axis had to move a rotation sensor that could be used to read out the position of the pendulum.
- To ensure that the pendulum could be made to swing again and again, only pulling it up by means of electromagnets proved practical. For this purpose, a motor is needed for each pendulum, which drives an iron plate to the magnet attached to the loudspeaker and, after switching on the electromagnet, pulls the pendulum up to a certain height (horizontal line). The iron plate is attached to three non-stretchable chutes (braided fishing line): One on the left and one on the right hold the plate at the correct working height and track, and the third is fixed in the center of the plate and can be wound and unwound by the motor onto a spool. The pendulums are not released until all pendulums in a combination are raised.
The sensor taps and switching of the electromagnets are done via an Arduino connected to a Mac Pro running the control program and sound generation (MaxMSP/Javascript).