Frequencies and Hermann von Helmholtz’ very first synthesizer


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Frequencies can be sweet to our ears or utterly painful pending on what side of the scale you’re on. Many fine music artists are truly exploring the boundaries of frequencies, although probably the ones pushing the envelope the most are more experimentalists and more likely found doing installations at various art galleries. But before we move on a definition of frequencies may be in place: Frequency is the number of occurrences of a repeating event per unit time. It is also referred to as temporal frequency, which emphasizes the contrast to spatial frequency and angular frequency. The period is the duration of time of one cycle in a repeating event, so the period is the reciprocal of the frequency. As you can understand frequency is an important parameter used in science and engineering to specify the rate of oscillatory and vibratory phenomena, such as mechanical vibrations, audio (sound) signals, radio waves, and light.

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Helmholtz’s apparatus uses tuning forks, renowned for their very pure tone, to generate a fundamental frequency G  and the first six overtones which may then be combined in varying proportions. The tuning forks are made to vibrate using electromagnets and the sound of each fork may be amplified by means of a Helmholtz resonator with adjustable shutter operated mechanically by a keyboard.

By varying the relative intensities of the overtones, Helmholtz was able to simulate sounds of various timbres G and, in particular, recreate and understand the nature of the vowel sounds of human speech and singing. Vowel sounds are created by the resonances G  of the vocal tract, with each vowel defined by two or three resonant frequencies G  known as formants. When we say or sing ‘a’ (as in ‘had’), for instance, the vocal tract amplifies frequencies G  close to 800Hz G , 1800Hz and 2400Hz amongst others. When we require a different vowel sound, the muscles of the throat and mouth change the shape of the vocal tract, producing a different set of resonances G .

Today we are exploring three persons that are walking in the footsteps of Helmholtz and that are truly pushing the envelope in frequency exploration. First out is Nicolas Bernier who has made a number of videos in the field of frequency and frequency manipulation. Nicolas Bernier creates audiovisual performances and installations, musique concrète, live electronics improvisations and video art while also working with dance, theatre, moving images and within interdisciplinary contexts.

In his latest addition seven electromagnetically driven tuning forks are generating continuous acoustic drones by help of a custom keyboard/controller turning each frequencies on and off. The project is a poeticized take on the technical device invented in the late 19th century by physicist Hermann von Helmholtz (1821-1894) who created what can be seen as the very first synthesizer. Combining sound and slow light pulsation patterns, this « acoustic additive synthesizer » is creating a contemplative and intimate experience.

The monotone sounds created are delicately adjusted and manipulated through a simple keyboard, but the output is far from simple as it creates quite am ambient and hypnotic audio performance.

Next one up is ::vtol:: aka Dmitry Morozov, a Russian media-artist, musician and engineer of strange-sounding mechanisms.

::vtol:: is perhaps even more hands on than Bernier as often DIY type projects are set up and recorded. In this video the swinging robotic arm generates intriguing sounds and audio sound scapes. When the feedback sound pendulum is displaced sideways from its resting, equilibrium position, it is subject to a restoring force due to gravity that will accelerate it back toward the equilibrium position. When released, the restoring force combined with the pendulum’s mass causes it to oscillate about the equilibrium position, swinging back and forth. The time for one complete cycle, a left swing and a right swing, is called the period. The period depends on the length of the pendulum and also to a slight degree on the amplitude, the width of the pendulum’s swing. Looking to the set up we know that this piece called “warrior” is composed as follows:

feedback sound pendulum

– arduno nano
– servo motor
– electret mic
– lm386 amp
– speaker

Final performer in today´s frequency session is fuse*

Independent Frequencies is an audiovisual generative installation based on these principles. The sounds emitted by the installation are the result of the variation of the volume of 18 natural harmonics layered one on top of the other, and represented by the 18 circular columns. A pure sound is in fact associated with each column, the frequency of which is a multiple of the frequency of three fundamental notes that change cyclically. On each column, the frequency associated in that moment (white number) is visualized, together with its volume (red number).The columns with a red background are those representing the fundamental notes, which form the basis of the chords on which each set of harmonics is based.

Other sounds are generated cyclically with given rhythms that increase and decrease in intensity over time. The installation allows us to move the sound 360° around the onlooker, and the origin of every sound is shown with a different visual effect on the columns placed in the direction of each single sound.

MEDIAgarden CUBO
MEDIAgarden is an installation placed in the two gardens of the head offices of Unipol in Bologna in via Stalingrado, comprising 41 columns with high luminosity RGB LEDs. The centre of the installation lies in Piazza Vieira De Mello in Bologna, where the light columns are laid out in a circle, thus surrounding the onlooker. MEDIAgarden is part of the CUBO project created by FUSE*ARCHITECTURE.