The Sound Cube

The ‘Sound Cube’ in the foyer of the Mozarteum University Salzburg,

A Sound Art Project by Johannes Kotschy.

The world of tones is not merely limited to the twelve tempered semitones as we know them from the piano – but we Europeans became truely familiar with that not before we got to know exotic sounds, the so called "non-European music". Music is played all over the world, and often in completely different tone systems. Additionally to our customary pitches, they result in a braid of many microtones whose systematization is still waiting.
The composer Johannes Kotschy holds the view that the different tone systems need a common starting point, and he sees it in the physically given naturetone series as originating from each vibration of a string or of an air column in wind instruments. He composed a network of microtones from the connection of tone systems with each other in tonal relationships, in which all tones are in a relation of free vibration to each other – made audible with an instrument of fine-tuned brass tubular bells.

The ‘Sound Cube’, presented for the first time at the first Biennale in Salzburg, in , contained 100 of these brass tubular bells with a length of 80 to 160 cm. Fixed side by side, they would cover a wall of 15 m length — that's why they were situated with less space requirements in nine rows in a cube-shaped steel construct. Though, this visually impressive sound art object had the disadvantage that it was impossible to strike the tubular bells lying inside in a conventional manner with hammers.
The composer solved this problem by means of electromagnets which make the tubular bells sound, controlled from a console. It took a number of experiments to find the appropriate hammers and stroke techniques: after one year of intensive work, the new ‘Sound Cube’ could be presented with a novel playing technique, on in the assembly hall of the former townhall of Mondsee in the Salzkammergut.

Actually, a variety of tone scales can be played with this instrument, which has an ambitus of 2 ½ octaves, Pythagorean temperaments and just intonation, as well as Arabian Maqamat and Javanese Slendro and Pelog scales. In order to play the instrument with more effect Johannes Kotschy has planned further technical improvements — the keyboard shall be programmable and thus be simplified, and the resonances of the tubular bells with their standing precise sounds shall be amplified by pick-ups. His aspirated goal would be to extend the tone repertoire to 4 octaves with 256 individual tones, in total.

Festival "Kraftklänge" on the Irrsee (Salzkammergut) with the ‘Sound Towers’ by Johannes Kotschy,

Johannes Kotschy initiated the project in , at the festival "Kraftklänge" on the Irrsee in the Salzkammergut. Three pyramid-like towers, each assembled with 13 tubular bells, were set up on boats and played on the lake, and the sounds, transmitted via radio microphones, were mixed by an installation on the shore. These at the same time originating novel sound combinations were the composer's motive to further engage himself with the Sound Towers — they were presented in the very same year at the Musiv festival in Salzburg and on the occasion of the Microtonal Week in autumn 2008 in the foyer of the Mozarteum University Salzburg in an already modified form. But it was not until the ‘Sound Cube’ that a complete instrument finally came into being.
It represents in a certain manner an onward development of the Zoomoozoophones, designed by Harry Partch in the seventies, and constructed by Dean Drummond in New York, since it includes not only the seventh and eleventh intervals that are not used in our familiar tone system, but also the thirteenth naturetone by which of course the tone repertoire increases considerably. With its 100 tubular bells, it is probably today the largest instrument of its kind in the world.

In contrast to aluminum tubes, the tuning of the brass tubes used here, provided by the DIEHL-Metallwerke, Röthenbach an der Pegnitz near Nuremberg, depends on many factors:

  • on the type of alloy and on the specific weight,
  • on the diameter,
  • on the side thickness,
  • on the tube length,
  • and on the drill hole (vibration node).

Surprisingly, there is a relatively simple mathematical interrelation between the tube length and the pitch for quite equally composed tubes: the ratio of the two pitches that form an interval corresponds to the inverse ratio of the square root of the tube lengths. This can be seen almost analogous to the ratio of vibrating strings or air columns — just in contrast to this, the clincher for the pitches of the tubes is the square root of the proportion of length.

With the tubes measured that way, harmonic series on 11 different fundamental tones can be generated, in addition to 8 different undertone series. Of course, they correspond with the ground tone of the instrument C: The dominant, subdominant, and the dominants of the dominant result in the fifth series

B -- F -- C -- G -- D

with their harmonics, furthermore the scales of the upper and lower third, of the upper and lower natural seventh, and of the eleventh overtone and undertone. But this is not the end: Further metal tubes will increment the total number of playable tones at first to 144, and finally to 256, on completion of the project.
Since the tones are controlled by a console, it will be possible to generate the most different combinations from 11 harmonic scales, but also combinations from undertone and overtone series. These sounds will be absolutely new, because they could not as yet be constituted with instruments — such sounds are at all events generatable by means of computer engineering. This gives an occasion to break musically fresh ground!

Technical Specifications

Dimension of the outer cube: 2.84 × 2.84 × 2.84 m
Dimension of the inner cube: 2 × 2 × 2 m
Weight: approx. 600 kg
Length of the brass tubes: 76 - 160 cm
Diameter: 55 mm each

There are installed: 700 m wire, 100 electromagnets with push buttons, and hammer-sticks constructed specifically for that.