Introduction

Definition of a sound structure

A musical instrument, when it does not fall in the idiophonic category (cymbal, triangle, bowl or « singing » glass...) is defined by its structure in the following manner : vibrating element type receiving an excitation, collector element type, diffuser element type.

The fundamental characteristic of the BASCHET work lies in the synthesis, or the structuring, of a number of new principles not revealed in the musical field and of a number of findings, mainly linked to the acoustic nature of metal :

Use of a new acoustic principle (framed metalic rod):

A metal axis placed at one end can be made to vibrate, various vibratory modes are obtained by twisting it thus different sound timbres.

Different assemblies can fix a frequency, in order to obtain non complex sounds.  Its dimension and material then influence in an essential manner the frequency of the resulting sound.  When this axis is very short, one part or the whole (resonance phenomenon) of the structure is made to vibrate, the lowest sounds appear.  However, a large dimension axis will create bass, full and « singing » sounds.

Sound conduction in metallic circuits :

A collector gathers vibrations, its nature (material, mass, dimensions) modifies the nature of the sounds created (propagation time, or keyboard response to the excitation, resonance, timbre).

In other respects, the collector takes the role of an interface between the diffuser elements and the support element.  A number of collectors can be linked together.

Bags, diffusing cones, metallic sheets amplification:

The first invention of the BASCHET brothers lies in the use of a self-supporting balloon playing the role of an amplifier.  They worked at the development of this device and tested metal amplifiers, metal sheets allowing for the amplication of sound signals and their deformation (distortion) through saturation.  They finally reached the cone-shape which brings more depth to the diffused sound and expresses more neatly the original frequency.  The composite materials then appear in the BASCHET instrument production.

Excitation with cristal bows:

There are a great number of exciters.  Let's mention for example the stick, the bow, the plectrum.
Glass bow excitation is a principle used in chemistry laboratories from the 18th century.  It is the main characterictic of the BASCHET Cristal.

Adding of effect systems :

Acoustic and experience teach us how a vibration, after being generated, spreads in the air.  For instance, the resonance time will be modified by adding mass in the structure, although at the same time it will influence the response time of the instrument.  The intensity and timbre of some frequencies can be enriched by adding sympathetic strings.  Directional diffusers can be made to move in order to create a « vibrato » effect.  Within the rest of the text, we have attempted to show, for each of the sound structures, guidance in terms of order :

- Historical
- Musical : play function of the musical gesture
- Acoustic : type of sounds, keyboard organisation
- Technic : weight and dimensions