The clavioline is a monophonic electronic musical instrument. Invented by the French engineer Constant Martin (1910-1995) in the 1940s, it is considered one of the precursors of the synthesizer.

After his engineering studies, Martin focused on the development and marketing of radio receivers. He also experimented with electronically generated sounds. These experiments led, in the early 1940s, to the construction of electronic bells and organ. They were heard from the tower of the Versailles city hall during the liberation in 1944.

Martin's most important achievement, however, is the clavioline. On May 3, 1947, he filed a patent application with the French Ministry of Industry and Commerce for an "electronic musical instrument", alias the clavioline. The patent (No. 946.629), granted on December 27, 1948, was published on June 9, 1949. By then, Selmer must already have been a privileged partner since the patent showed the image of a Selmer keyboard. Later, Martin had the instrument built by other licensed companies. In addition to Selmer in Paris (Société Le Clavioline) and London (Selmer London), keyboards were also  manufactured in the United States (Gibson Standard Model), Germany ("Bode Clavioline", "Tuttivox" and "Jorgenson Clavioline") and Italy ("Ondiola"), all based on the Martin patent. This common practice at the time helped the instrument gain popularity. In 1949 Martin also built a prototype of the "keyboard duophone", an instrument capable of playing two notes at the same time. However, this model was never commercialized. 

The clavioline consists of two parts (see fig. 1): the keyboard with sound generator and control panel and the tube amplifier with loudspeaker. These two parts are connected by a cable. Underneath the keyboard is a knee switch that adjusts the volume (see fig. 2), nicknamed "the soul of the keyboard" in a Selmer London sales catalogue. Initially, the keyboard had to be fixed under the keyboard of a (grand) piano. The musician's right knee can adjust the volume (see video), but experienced musicians master the technique so well that they also manage to obtain staccato effects. The clavioline can also be fixed on a stand, even if this system is not as stable in all brands.

The keyboard has a series of 36 keys (3 octaves), from F to E''''. An additional octave can be added on the bass and treble side, which brings the instrument to 5 octaves. This is possible by moving one of the two small levers located under the mark to the left (bass) or to the right (Ontreble) (see fig. 3). Small potentiometers on the sides allow a fine adjustment of the instrument (see fig. 4).

On the frontside, the instrument has 18 buttons ('register buttons') (see fig. 2). 14 are used to modify the sound. They are numbered from 1 to 9 and completed by the 4 filter coils O, A, B and V, and P (Percussion/Attack). The other 4 buttons (vibrato I-III and amplitude+) enable to change the vibrato. Figure 5 shows a scheme proposed by Selmer, for imitating the timbres of the best-known acoustic instruments.

The basic sound (timbre) of the keyboard, i.e. the one produced when no buttons are pressed - is graphically presented as a trapezoidal wave, similar to a square wave). The "trumpet" register is based on this sound, supplemented by an additional vibrato (see fig. 5). The other sounds/timbres are based on this basic sound, modified by the application of high-pass and low-pass filtering. But what makes the sound of the keyboard so unique and difficult to imitate on contemporary synthesizers is the amplifier. Selmer states: "The amplifier is of an unusual type in that a large amount of distortion is deliberately obtained. This distortion is used to further modify the signal and contributes significantly to the construction of the original sound. The amplifier is therefore an integral part of the instrument”.

The mim has two claviolines, with inventory numbers 1995.033 and 2018.0134. The first one, presented in the galleries, is not playable. It was built by Le Clavioline (Type CM, series 1, n° 768). The second, acquired in 2018 (2018.0134), was restored by Daniel Kitzig and is a Selmer Type A -'Auditorium' Selmer keyboard with serial number 450, made in London. The auditorium model is the standard Selmer model. It was followed later by the Selmer Clavioline Concert. At the end of 1962, Selmer also launched a Concert Reverb model. Despite the little extra of reverberation, this model was not very succesful.

Does the sound of the clavioline sound familiar to you? This would not be surprising, as the instrument was relatively well known in pop music, even if that was not Martin's primary purpose. It is designed as an accompanying instrument, its timbres are the ones appreciated at the time. But it is not the possibility of stops combinations that makes the instrument so attractive. It is rather the possibility, for musicians, to create one’s own sounds. That is what made its use contagious! This is also the reason for the use of the clavioline in pop music, mainly in the 1960s.

Two songs stand out in particular: Telstar by the Tornados (1962) and Baby, you're a rich man by the Beatles (1967). In Telstar, the main melody (played by the clavioline) is deeply imprinted in our memory. In Baby, you're a rich man, the clavioline imitates a shehnai (Indian oboe) and it alternates with the voice. The song was released on the B side of the single All you need is love. According to rock journalist Gordon Reid, it was the clavioline that made this song famous: 'John Lennon's experiments on the keyboard are best remembered, with an apocryphal story suggesting that it was by rolling an orange on the keyboard that he created his moaning, now so famous'[1]

That the clavioline was played in the song Telstar is not surprising. The title of the song refers to the satellite with the same name. This is the first communication satellite launched by the Americans, which had (among other things) to provide transatlantic transmission of live TV images. In this spirit of technological exploration, the clavioline could not be absent from the musical genres in full development: pop and rock music.

An anecdote completes the history of the Tornados. The band's guitarist, George Bellamy, is the father of Matthew Bellamy, leader of the rock group Muse. The guitar sound of Muses' song Knights of Cydonia(2006) refers directly to Telstar's keyboard. And the structure of Knights of Cydonia can be compared to Ridin' the Wind (1963) by the Tornados, a song written by George Bellamy.

If the clavioline is used only occasionally by the Tornados, this is not the case with the Dutch group The Hurricane Strings. Like the Tornados, this group was formed in the early 1960s, and they played instrumental music. But for Hurricane Strings, the clavioline is part of the set of fixed instruments. It is also present in many official photos of the group (see fig. 7). The same is the case with the Maylegends group, of which Byron Elwell is the clavioline player. The latter said after hearing Telstar (and the clavioline): 'It blew my mind when I first heard it.... It sounded like something between a crying cat and a distorted keyboard. I thought I should create this sound['2].

However, the clavioline was already known long before the Tornados. In 1953, it could already be heard in Frank Chacksfield's Little Red Monkey, as well as in the BBC's science fiction trilogy Journey into Space. In 1954, the instrument even appeared in the Bollywood Nagin production, in the melody of the snake charmer man dole mera tan dole mere dil ka gaya karar. It is also used in Microcosmos (for clavioline, guitar, musical saw, vibraphone and xylophone, percussion and piano, 1957) by the Japanese musician Toshiro Mayuzumi, as well as in Runaway and Hats Off to Larry by Del Shannon (1961). In this last production, however, it should be noted that it is a clavioline radically modified by the musician Max Crook, who calls his instrument "Musitron". Finally - and we are already in the second half of the 1960s - we mention the albums The Magic City (1966), The Heliocentric Worlds of Sun Ra - Volume Two (1966) and Atlantis (1967) by jazzman Sun Ra.

Despite the clavioline's exceptional sound qualities, its future will not be as bright as one might have thought. This is largely related to the development and commercialization of the first synthesizers in the second half of the 1960s, particularly those produced by Robert Moog.







Ben Marks, The Otherworldly Sounds of the Clavioline, from Musical Saw to Wailing Cat, in Collector's Weekly:

Constant Martin, La musique électronique, Paris, 1950.

G.H. Hillier, The Clavioline, in Electronic Engineering, vol. 24, nr. 296, 1952, p. 454-5.

Gordon Reid, The Story of the Clavioline, 2007, in Sound on Sound:

Brevet d'invention, nr. 946.629, published on June 9, 1949.

Clavioline, Selmer, Paris, 1949, inv. 2018.0134
Kneestop and stop button, Clavioline, Selmer, Paris, 1949, inv. 2018.0134
Transposition’s kneestop, Clavioline, Selmer, Paris, 1949, inv. 2018.0134
Fine tuners, Clavioline, Selmer, Paris, 1949, inv. 2018.0134
Table of stops, Selmer London (source:
The Hurricane Strings (source: