Name : EagleTar2®
Family : Plucked strings / “Lute” family
Date of creation : 1996
Musician : Georges Alloro

Currently in production, this instrument is the acoustic version of the first EagleTar®. Also carved in solid ash wood, its sound board is made of python skin stretched on a chiselled ash structure. This structure divides the main membrane into cells like alveoli, of different shapes and sizes, so that they are never the same. On the back is a sheet of stainless steel of the same style, only in reverse and bulbous. Each part of the membrane is thus completed by a closed volume that creates an acoustic reflexion.
This instrument has both sympathetic and rhythmic strings.

Name : EagleTar®
Family : Plucked strings / “Lute” family
Date of creation : 1990
Musician : Georges Alloro

The shape of this instrument ends with an eagle’s head from which it gets its name. It is made of solid ash wood with a polycarbonate sound board, a duralumin skeleton and a titanium tension control bar. All of this is needed to hold the tension of the instrument’s 23 strings. Each of the materials used to make the pieces was chosen for its qualities in function to the purpose of the piece. The coherence between the shapes and materials makes this prototype an example of what contemporary technologies and materials can bring to the manufacture of stringed instruments today.
The instrument’s neck supports 8 melodic strings. Half of the 4 first strings (guitar type strings) have frets while the 4 others (bass guitar type strings) have a smooth fingerboard. 15 harmonic strings (2 heptatonic octaves) are set along the body of the instrument following the classic arrangement of guitar strings so as to be played in a low key or in arpeggio.

Name : StickTar®
Family : Plucked and strummed strings
Date of creation : 1987
Musician : Georges Alloro

The StickTar® is formed by a long neck made of laminated wood and bamboo, and has polycarbonate mobile frets.
The tension of the 5 melodic strings is created by screw devices on one side and a constant tension control system on the other side. This system allows one to tighten and loosen a group of strings of different lengths while keeping the same intervals.
The tension control system compensates for the small width of this instrument’s neck which prevents any “dragging” or “portamento”.
The acoustic expansion can be done in two ways:
- by using a magnetic sensor placed between the metallic strings and the harmonic strings,
- by suspending a web of silk threads between the base of the melodic strings and a large tense membrane in a frame.
It is possible with this system to increase the acoustic power of an instrument as well as making the low tones deeper.

Name : Violon-Arlequin®
Family : Strummed strings
Date of creation : 1987
Musician : Georges Alloro

This instrument is a spiked violin inspired by the Persian kamantché technique. Its name comes from the great diversity of materials it is made of (wood, Plexiglas, polycarbonate, duralumin, titanium, bamboo, snake’s skin, synthetic skin). It has 4 melodic strings (violin) and a group of 9 harmonic strings which go under the bamboo finger board, then at two levels, into the bridge under the melodic strings. The bridge is pressed onto a piece of snake’s skin glued to an exponential shell: the vibration of the skin is compressed and generates an acoustic expansion.
The spike on which the violin is supported allows the instrument to be rotated which makes it easier for the bow to go from one string to another.

Name : Altar-Inox®
Family : Plucked strings / “Lute” family
Date of creation : 1986
Musician : Georges Alloro

Made of stainless steel, it has a bent and rippled finger board that has frets, five melodic strings, two rhythmic strings and twelve sympathetic resonant strings. The bridge is only semi-attached and can support resonators. On the bridge itself, a bevelled screw device reveals the harmonics of the different strings.
The AltarInox® is the first instrument to which an internal sound board has been adapted.  This board extends under the finger board, inside, and creates a big sound for a small instrument like this one.
This instrument was designed following the “veena-guitar” and, allows, in the same way, modal tunes to be played with a technique close to the one used when playing the guitar.

Name : KotarIV®
Family : “Zither” family
Date of creation : 1984
Experimental instrument

The KotarIV® is a didactic instrument created for the study of micro-intervals. It is the outcome of long hours of research on mechanical methods of controlling string tension.
It is equipped with 11 mechanical devices allowing the chord to be changed and to lower or raise the note. Thanks to its colour code, it is possible to visualize the past intervals and thus to become familiar with the use of micro-intervals.
When the mechanics are at rest, they automatically go back to the same note, a basic note that can be set. 

Name : KotarIII® (with mechanics)
Family : “Zither” family
Date of creation : 1983
Musician : Created for Ustad Zia Mohiuddin Daggar, Dhrupad tradition master (northern India)

It is with the KotarIII® that the curved body of the table takes its definitive shape. It is composed of two constrained sheets of wood that form a volume instead of just one sheet as for the KotarII®. Although it is very light, it is also extremely strong and resistant. The 15 melodic strings have harmonic-emitting bridges that will replace, from now on, the bevelled screw device. A mechanical system made of polycarbonate, placed on the bridge, allows the string to be stretched far more easily than manually, as in the previous examples.
Furthermore, the instrument has 3 groups of two rhythmic strings inserted between the two octaves of melodic strings.

Name : Altar25®
Family : Plucked strings / “Lute” family
Date of creation : 1982
Musician : Georges Alloro

This instrument, which could also be called a double bass mandolin, is made of 120mm diameter bamboo. The elements (frets, finger board and tables) that it consists of can be moved and are interchangeable. 25 melodic, sympathetic and rhythmic strings go from the finger board to the peg board by passing through a semi-attached bridge. This bridge is not fixed to the table but directly to the strings and transmits the vibrations to a stretched skin on an ovoid closed volume through rigid threads.
The frets and bridge are made of polycarbonate.

Name : KotarII®
Family : “Zither” family
Date of creation : 1980
Musician : François Bourlier

Like the KotarI®, this instrument was inspired by the Japanese Koto. Its large size, 160cm long, allows an important increase of the acoustic power and the length of the sound. These sound qualities are necessary to work on the modulation of sound during the length of a note, as in the Drhupad (a northern Indian traditional type of music).
The KotarII® uses, for the first time, a construction technique called “curved body”: the wooden table is bent into a curve by a strong restraint giving the instrument an exceptional rigidity. The table supports 22 melodic strings and four strings played in drone. Each of these strings has a bevelled screw device allowing the harmonics to develop.
In 1981, one of the great masters of Drhupad tradition, Ustad Zia Mohiuddin Dagar, met Georges Alloro while on tour in France. He was won over by the KotarII® and found it so adapted to Dhrupad that he considered introducing it into India under the name Mandala-Veena. He died before this project could be finished but it has now been taken up again and is under study.

Name : Altar-Viridis®
Family : Plucked strings / “Lute” family
Date of creation : 1980
Musician : Georges Alloro

The body of this instrument is composed of a large piece of bamboo of approximately 120mm diameter. On each end, two bevel shaped cut-outs leave place for the tailpiece and pegbox. A cypress finger board on which are set 27 metallic frets is inserted in the middle of a long slit that runs along it. A sound board is adjusted to the bottom part of the instrument and holds 6 individual bridges built on the principal of harmonic bridges also called flat bridges (they allow the emission and enhancement of a string’s harmonics, as on the Indian sitar and Tampura). This instrument was initially designed for a study of a type of classical northern Indian music called Dhrupad. In 1994, the Altar-Viridis® was transformed to integrate the MIDI system.The body of the instrument is thus increased by 14 magnetic, ceramic and other sensors. A control device is placed inside the instrument’s body, which on one hand allows the different MIDI programmes to be piloted and controlled, and on the other hand to mix effects and expanders.

Name : KotarI-Inox®
Family : “Zither” family
Date of creation : 1976
Musician : François Bourlier

This instrument belongs to the zither family and its high bridge dividing the strings in two parts is inspired by the Japanese Koto. By pressing the part situated behind the bridge, one can control the sound modulation up to fourth, even fifth.
The KotarInox® is made of a stainless steel sheet, used as a sound board. Its curved structure made by the bending of the metal sheet, gives the instrument great rigidity and enables it to resist the tension of the strings.
A device of bevelled screws placed at the end of the strings generates the emission of the harmonics.

Name : Pentoctar®
Family : Plucked strings / “Lute” family
Date of creation : 1973
Musician : Georges Alloro

This stainless steel instrument has a mobile set of frets that enables the scale to be changed in order to use micro-intervals. It has a range of five octaves and covers the tessitura of the guitar and the electric bass.  It has eight melodic strings and two rhythmic strings. The tuning is ensured by the rectilinear mechanics placed at the top of the instrument. Its amplification is identical to that of electric guitars.

Name : Tarbass®
Family : Strummed strings
Date of creation : 1971
Musician : Georges Alloro

It was on this instrument that the semi-attached bridge was used for the first time, with the bridge fixed straight onto the strings and supporting the resonators. The tessitura of the Tarbass® covers a range of more than five octaves, reuniting the ranges of the cello and double bass.
The neck is made of a hollow stainless steel cylinder, on one side are 6 melodic strings and on the other is a series of sympathetic strings. This lay-out allows an even distribution of the tension of either side of the instrument’s body. At the level of the bridge, the strings are maintained by 2 metallic hoops that hold the resonators. These resonators can be made of different metals or other materials such as wood, skin or composite materials. They can be removed so as to change the instrument’s acoustics at will. 

Name : Twintar®
Family : Strummed strings
Date of creation : 1971
Musician : Georges Alloro

This double instrument was made in order to use, while being played, all the possibilities of fret instruments (sound precision and chromatic intervals) and of instruments with smooth finger boards (glissando). This rotating movement is made possible by the turned wooden base on which the instrument stands.
The Twintar® can be played with a bow as well as in pizzicato.
 

Name : Stringar®
Family : Strummed strings
Date of creation : 1970
Musician : Georges Alloro

This very large instrument (2, 20 m), made of metal and rare wood, was inspired by the Indian Sarod and the bass violin. It has a hollow neck with a smooth finger board supporting 54 melodic, rhythmic and sympathetic strings. This neck transmits the vibrations from the sound box to the metallic resonator at the other end of the instrument. A tailpiece with micrometric screws allows a fine harmony of all the strings. Acoustic amplification is obtained through using a copper sound box on which is stretched an animal skin.

The unusual size of the skin (wider than its height) and the tension system gives a whole scale of acoustic adjustments that considerably change the sound characteristics of the instrument (longer notes from the harmonic strings, control of the phasing phenomenon, amplification of the low frequencies).