The ‘Clavecin Magnetique’. M. l’Abbé Bertholon. France, 1785

M. l'Abbé Bertholon's 'Clavecin magnétique'
M. l’Abbé Bertholon’s ‘Clavecin magnétique’ of c1870

The ‘Clavecin Magnetique’ was an early acoustic carillon type instrument operated by magnetic attraction. The instrument was the result of an experimental enquiry into the nature of magnetism and electricity – much in vogue at the time – by Abbé Bertholon de Saint-Lazare (1741–1800) a Jesuit priest, mathematician and ‘natural scientist’ in Montpelier, France. Bertholon’s invention was a simple instrument which produced sounds by attracting metal clappers to strike tuned bells by raising and lowering magnets operated by a keyboard. Bertholon wrote and published many booklets regarding the phenomena of electricity and magnetism and their potential medical use. In ‘Du Clavecin magnétique’ (Paris, 1789) Bertholon referenced and praised two other keyboard instruments as influences on his design; the ‘Clavecin Électrique’ of Jean-Baptiste Delaborde (France. 1759) and Louis Bertrand Castel’s ‘Clavecin Ocular’ or ‘Colour Organ’ (Paris, France 1725) and then proceeds to explains the function of his instrument:

Frontispiece of 'Du Clavecin magnétique'. by M. l'Abbé Bertholon - Bertholon, Published in Paris 1789.
Frontispiece of ‘Du Clavecin magnétique’. by M. l’Abbé Bertholon – Bertholon, Published in Paris 1789.


Extract fromM. l’Abbé Bertholon’s ‘Du Clavecin magnétique – extrait de La nature considérée sous ses différents aspects, ou Journal d’histoire naturelle’

“Those things that really excite curiosity are often likely to be the subject of greatest utility. The history of science & art could provide several examples of this truth: when the Philosopher Thalès of Miletus, six hundred years before our era, discovered the property that when amber was rubbed it attracted small objects, no-one was tempted to believe that this discovery was anything but a vain & useless phenomenon; & we were far from understanding that this property, so small in appearance, may one day lead the bold race of Prometheus, to drop at will his fire from heaven, to divert lightning, and to master it in many ways.

With what was haughty scorn would some of the ignorant contemptibles have shown to this illustrious philosopher, the founder of the Ionic sect, when they saw him busy and seriously rubbing amber to attract small straws? This however is the first phenomenon of electricity, we will need to use all of our  knowledge on the subject to achieve the art of  preserving lightning and even to provide the cure of some chronic diseases until now have rebelled against remedy.

The first discoveries of aeriform fluids, known as Gas, have also seemed strange and yet they led us to the knowledge of certain mineral waters, the art of how to cure cancer & dissolve [kidney] stones etc.

Could the first person to observe that magnets attract iron & have conveyed to him their virtue, have imagined that one day, using an iron or steel needle, that he would brave the fury of this treacherous element and the needle, by flying from one pole to another allow him to strike out on unfamiliar roads.

Those who are involved in the search for truth, must ignore the curses of blasphemous people, and continue to question with a stubborn confidence the oracles of nature, because all knowledge is related to each other and interlinked.

The discovery of the magnetic harpsichord would always some interest, when she was only an object of curiosity, since all the truths are valuable, and that they lead almost always has benefits far at least, whatever the weak eyes can glimpse.

But it’s not just the degree of usefulness provided by the magnetic harpsichord, there are others that immediately arise. Everything that is capable of producing movement in the universe and can effect different bodies either immediately or delayed, and move without visible touch if necessary, unquestionably cannot be ignored.

We know several different types of Harpsichords [‘Clavecin’]; the ‘Ordinary Harpsichord’, the Ocular Harpsichord, & the Electric Harpsichord [‘Clavecin Électrique’]. The first is a purely acoustic stringed instrument; the second one once created quite a stir. Pére Castel [Louis Bertrand Castel  -15 November 1688 – 9 January 1757 French mathematician and inventor of the ‘Clavecin Ocular’ ], is famous for the products of his brilliant imagination, compared the seven colors to the seven tones of Music.

The natural or diatonic order was according to him:

  •  ut; Blue,
  • Re; verd,
  • Mi; yellow,
  • Fa; fawn,
  • Fol; red,
  • Le; purple,
  • Si; gray,
  • Ut; blue.

When two [of these] instruments are played and run in parallel it would create a new harmony, a melody of sounds corresponding to their colours.

This famous Jesuit [Pére Castel] does this purely to give the deaf the same pleasure that we feel from music. We would have been able to play music, using only colours, the same tunes we have heard on an ordinary harpsichord – there would be sonatas for the eyes as there are for the ears: the soul of the blind could have experienced the same enjoyment from the sounds as deaf by the eyes; &  both experience the same piece of music, since it could have played to the eyes a Piano, an andante, a presto, a prestissimo, as we play to the hearing.

The third harpsichord which I previously mentioned is the ‘Clavecin Électrique’ of Pere DeLa Borde[the Jesuit priest Jean-Baptiste Delaborde of Paris, France, inventor in 1759 of the Clavecin Électrique ] . It consisted of a single rod of iron on silk cords [the beater], with bells of different sizes for different tones. Two bells were combined in unison for a single note, one has suspended the iron rod with a brass wire, and the other with a silk cord. The beater is suspended by a silk thread and falling between two, etc. by electrifying the lever, the machine was put into play if each key meeting its lever, and each lever to its timbre.

The new harpsichord that I have imagined for some time is the ‘Clavecin Magnetique’, which has nothing in common with, and a very different structure from the preceding instruments. The whole machine is based on magnetic attraction of the physical spirit; that is – it attracts, & shakes iron battens hanging in balance with a range of tuned bells between them. You can hear tones that have known relationships, and suites of tones that form a nice melody.

For this effect, simply press the keys, lowering the end of a few levers which raise the other end on which is placed a bar magnet held in position by two parallel & perpendicular frames pierced by holes for receiving the bar magnets: the upper end of each bar, rising for each corresponding pitch, attracts the batten which is hanging out & to the side: This attractive force  knocks the bell & creates it’s own sound. . If two bells are played in unison, the third, the fourth, fifth or octave, being struck by the movement of the lever, we will hear these corresponding tones, and therefore we, can play different tunes, that is to say, we hear, singly or in succession, a series of tones that will have a definite relation between them. The soul of the movement that produce sounds in the harpsichord, the physics engine is the magnetic attraction, which have not yet been used to produce this effect we will have a magnetic harpsichord.

The physical engine and the soul of the movement that produces the sounds in the harpsichord is magnetic attraction, which has never before been used to produce the effect that we have in this magnetic harpsichord.

Let’s get into some detail, and show some experiences that can be seen as the foundations of the magnetic harpsichord;

A magnet attracts a piece of iron or steel. The distance of the magnet is proportionate to the attractive force of the magnet. This experience is very well known & not contested. The iron is presented and the magnet attracts until a meeting takes place. We can create a magnetic property very easily in steel bars  & this property is strong. Physics has prescribed several ways to magnetise the iron & steel

The action of the magnet exerts itself, as experience shows, despite the interposition of all objects except iron: and the attraction takes place, whatever has been put between the attracting object & attracted object; gold, silver, copper; or any other metal that does not contain iron, even though there is between them glass, wood, stone and other animal products, vegetable or mineral.

What are the facts which form so undeniable experiences. Let us assume now that a patch of glass or copper & a clapper of metal are suspended near each other, it is clear that bar magnet, which rises in the interior of the bell at the height of the clapper attracts it & the clapper will hit the bell, which will result in a sound, and that this effect will still take place, where distances can not be too large, but proportional to the attractive forces.

If two bells are played in unison, we hear that each of them will resonate; they are likely to have an effect each other, such as the octave, the third, the fourth or the fifth, we hear the formation of a regular harmony when played at the same time or a nice melody if they are played successively. And it can make all sorts of sounds, it will be able to play all the tunes that you will want, if it was a series of bells in the key of ‘tri’ & stored in the order of succession & natural tones sharps & flats, in a manner similar to that of different Musical instruments, it will result in a true magnetic harpsichord.

Bertholon's engraving of the workings of the 'Clavecin Magnetique' referred to in the text.
Bertholon’s engraving of the workings of the ‘Clavecin Magnetique’ referred to in the text.

The first figure represents the bell F G with the clapper G, suspended on I rope or rod H K. The magnetic bar is carried by the end C of the lever CD , and the lever, which is supported by its axis A & its fulcrum, is pivotable, when a finger is pushed on D: The whole thing is supported by the pivot BA; & as soon as we stop this pressure, the weight of the bar makes the lever fall, and there is no more attraction.

We see in the second figure that the same magnetic bar AB, placed horizontally, may, when it is high in C, D, attract. at the same time the clappers F, E, which then hit the bells C D. To produce this effect, simply lower the G end of the lever.

Since it can be very difficult, and consequently very expensive to find a large number of silver bells or even copper or brass, which give different tones in desired relations, one can order the base of the cups as in B, 3, and select a number that can give several series of octaves. To explain more perfectly, we can put more or less water in those cups that would render the desired tones. Then, by raising the tip of the bar magnet C at the height of the clapper A, the tone that one wants will be made.

Figure 4 corresponds to Figure 2, and show that the AB bar being placed horizontally, it may, by a single movement G, raise the bar to the level of the two clappers C, D & pull together to sound two tones in unison, octave, or third, or fourth, & , accordingly the base of the cups will be selected.

The arrangement as seen in Figures 2 and 4 give the complete instrument dimensions that by their size would hit awkwardly. To make this more readily understood, we represented the length of the bars in a position parallel to the width of the body of the man who plays the instrument; but if we place the bars in one direction always parallel to the horizon, and perpendicular to the direction of Figures 2 & 4, then the portion of the instrument; between D & C, in Figure 4, we have, instead of the whole length, the width of the plank upon which the cups lie, is perhaps equal only to these. In this case you can store quite a large number of bells or cups in size equal to the extent that one can easily browse with both hands to press the buttons D, G, G, G.

Figure II of the board is a line or row of bells in the simplest arrangement, to avoid confusion it is a series of bells, such as one sees one in Figure I, Plate I. It is understood that one can play a simple tune, if you have a diatonic or chromatic series of bells. Two planks drilled with corresponding spaced holes always retain the perpendicular position of the various magnetic bars.

We can, according to this arrangement and that of  figure2 and 4, design a third engraving where the same bar would move at the same time. two clappers would hit each bells in agreement.

It can be seen in the second diagram that each clapper is closer to one than the bells neighbouring bell, so that when the clapper returns after attraction, we can not hear a second sound.

If we still assume that the bells & clappers are arranged in parallel lines between them, but gradually higher than the first line of bells & clappers of the second board, we can, in a small space whose depth is increased , have a double, a triple, a quadruple row etc. of bells, if there are two, three, or four of these lines. In this way it will be easy to place several corresponding levers in a very confined space, so that there are some keys in rows above the other; & then the harpsichord be no larger than the ordinary instruments of the same name, it will be easy to play the harpsichord, and even to make it portable.

When the bar magnets have lots of energy, their attraction is very strong, and because the distance between them and the clappers are small, it sometimes happens that after the first shock & after oscillation or vibration, the clapper can still hit the bell.

To turn it off you can use a type of damper or shock absorber. For this purpose, between the node 1  &, Figure I, there is a pulley on which is passed a small wire or cord attached at one end to a point between A & D, while the other end of the wire will be armed with a small piece of cloth with a lead ball for ballast. This being so, it is obvious that every time we push down the rocker lever D, it will raise the shock-absorber, and the shock will be made; but once you press the more preferred key, the weight of the bar by the action of the lever in opposite direction, the shock-absorber descends & will be between the clapper & the bell; it will then ascend, and allow free play.

I then found a way to make a more accurate alternative to the rise and fall movement of the damper, by fixing a wire or cord that passes over the pulley, so that one of its ends is attached between A & D, and the other end between A & C, and that a piece of cloth is placed positioned at the corresponding part of the cord between the bell and the clapper when the C lever is lowered.

A few years ago, after several tests & attempts and after many preparatory experiments, I finally came to build the magnetic harpsichord as I have described; & I was satisfied, as were those who saw the first performance of the instrument. There is no doubt that we can still simplify and perfect it, as normal for all inventions.”


‘Du Clavecin magnétique – extrait de La nature considérée sous ses différents aspects, ou Journal d’histoire naturelle’. Par M. l’Abbé Bertholon – Bertholon, Pierre ; Aubert pp. 321-332 + 332-359 + 361-362. Paris 1789.(translated: Simon Crab 2015)

The Denis D’Or “Golden Dionysis”, Václav Prokop Diviš. Czech republic, 1748

 Václav Prokop Diviš (1698 – 1765)
Václav Prokop Diviš (1698 – 1765)

The Denis D’or, the “Golden Dionysis”, was an early one-off  keyboard instrument built by the  Czech theologian and pioneer of electrical research Václav Prokop Diviš (1698 – 1765). Described as an ‘orchestrion’ because of its ability to imitate the sounds of wind and string instruments, it is often described as the first electronic musical instrument, yet, due to lack of detailed historical documentation and conflicting contemporary reports this claim remains uncertain.

Several accounts describe the instrument as an electro-acoustic instrument where the strings are vibrated using electro-magnets: “…In 1730 the Moravian preacher Prokop DIVIS generated sound by electromagnetic excitation of piano strings . He called his invention Denis d’or “ (Schiffner 1994 , p 62) and “His experiments were based on the electromagnetic excitation of piano strings , but could not prevail despite initially considerable interest to the public .” (Harenberg 1989, p 26 quoted in Ruschkowski 1983, p 347) yet this seems unlikely as the relationship between electricity and electromagnetism only became understood as late as 1820.

Other accounts suggest that the Denis D’Or was an elaborate joke whereby the performer could be electrocuted at will by the inventor

Denis d’or , an electric “Mutationsflügel” with one pedal , created in 1730 by the Moravian preacher Prokop Diviß of Prendnitz in Znojmo…This instrument was 5 feet long and 3 feet wide, with 790 strings . However, the suspension and the tautening of the numerous metal strings were much more elaborate. The ingenious mechanism, which had been worked out by Diviš with painstaking mathematical accuracy was such that the Denis d’or could imitate the sounds of a whole variety of other instruments, including chordophones such as harpsichords, harps and lutes, and even wind instruments. An untimely anti joke was that the player of the instrument could receive an electric shock whenever the inventor wanted.

(Reallexicon der Musikinstrumente, Curt Sachs1913, p 108)

Denis D’or named by Procopius Divisz , pastor Prendnitz in Znojmo in Moravia , in 1730 he invented keyboard instrument with pedals, which is the time that efforts in the area of instrument making became almost a caricature . The instrument was 1.57 meters long and 0.95 meters wide , and had a reference of 790 strings that could be tuned in  three-quarter hours to 130 notes.  This instrument allowed , among the sounds of almost all known string and wind instruments were represented , and even also loose jokes such that the player were given an electric shock as often as the inventor or owner wished. Apparently only one copy of this instrument was made which was purchased by the prelates of Bruck, Georg Lambeck

(Mendel 1872 , Vol.3 , p.110 )

Diviš charged the strings of the instrument with a temporary electrical charge in order to somehow “purify and enhance the sound quality” leading to the instrument being described as an “electronic musical instrument” ( Johann Ludwig Fricker after witnessing the Denis D’Or in 1753) . However, with intricate practical jokes in the salons of the nobility being fashionable at the time of the construction of the Denis D’or, it seems likely (and also taking into account the historical development of electro-magnetism) that the instrument was just one of the many proto-electrical gimmicks of the Baroque and Rococco period rather than a serious contender for the title of the first electronic instrument.



Reallexicon der Musikinstrumente, Curt Sachs1913, p 108

Peer Sitter. “Das Denis d’or : Urahn der “elektroakustischen” Musikinstrumente?”: Perspektiven und Methoden einer Systemischen Musikwissenschaft, S. 303-305. Bericht über das Kolloquium im Musikwissenschaftlichen Institut der Universität zu Köln 1998

Mendel 1872 , Vol.3 , p.110

SCHILLING , Gustav [ Schilling 1835 ] : Encyclopädie the entire musical sciences or Universal Dictionary of Music , Second volume , Stuttgart 1835/1838 .

Harenberg 1989 : new music by new technology? Computer music as a qualitative challenge for new thinking in music , Kassel 1989.

Schiffner , Wolfgang [ Schiffner 1994 ] : Rock and Pop and their sounds Technology – Theses – Title , Aachen 1994.

Hugh Davies. “Denis d’or”. Grove Music Online. Oxford Music Online. 7 Oct. 2009



Memorial page to Prokop Diviš


‘Clavecin Électrique’ . Jean-Baptiste Delaborde, France. 1759.


Clavecin Électrique
Clavecin Électrique Jean-Baptiste Delaborde, Paris, France, 1759

Built by the Jesuit priest Jean-Baptiste Delaborde in Paris, France, 1759, the Clavecine Électrique or the ‘Electric Harpsichord’ is one of the earliest documented  instruments that used electricity to create musical sound. . Despite it’s name The Clavecin Électrique was not a stringed instrument but a carillon type keyboard instrument using a static electrical charge (supplied by a Leyden Jar, an early form of capacitor invented by the Dutch scientist Pieter van Musschenbroek of Leiden around 1745) to vibrate metal bells – The mechanism  based on a contemporary warning-bell device (1). This method allowed the player to create a series sustained notes from the bells, similar to an organ:

Two metal bells tuned in unison are hung, one with a silk thread, one with a wire onto a metal rod itself both hanging free by means of a silk thread at each end. Based on the principles of static electricity a beater, also hung on a silk thread is alternately attracted and rejected by each bell as soon at is released through holding down a key, n  positive and negative fields being created in the bells.
(“The Harpsichord and Clavichord: An Encyclopedia” Ferdinand J.De Hen p71 Routledge 2007)
Jean-Baptiste de Laborde's book describing the Clavesin “Le Clavessin électrique; avec une nouvelle théorie du mécanisme et des phénomènes de l’électricité”
Jean-Baptiste de Laborde’s book describing the Clavesin “Le Clavessin électrique; avec une nouvelle théorie du mécanisme et des phénomènes de l’électricité”
Delaborde’s misleading name of the instrument was an intentional attempt to elevate his invention above that of a Carillon – a mere musical-box:
“The electrical matter has something of the soul, as air is to the body, the guardian of the bellows globe, and ‘the conductor of the wind-door. The key is in the organ as a brake, with which moderates the effect of the air, I posed the same brake on the electric matter, despite his sensitivity, his agility. The air trapped in the organ there groaning, so long as the organist, as another Aeolus, opened the doors of his prison. If at the same time he took away all the barriers that stop, another would not produce a great confusion and disorder, but he does it Sorting […] with discernment. The electrical matter abode even as it locked up, and you feel unnecessarily around the bells of the new harpsichord, to the extent that is given the freedom, coll’abbassare the keys: it then becomes with great rapidity, but ceases d ‘ operate, as soon as the keys reassemble. This kind of cymbal hath also an advantage that others do not have, that is that where it ‘cymbals ordinarj the non-continuous sound weakening; electric organ and harpsichord retains all the strength that the fingers remain on the keys. “
Delaborde added that during a performance in a dark room the listener’s “eyes are agreeably surprised by the brilliant sparks” that were produced by the instrument and that “the clavessin became at the same time audible and visible” . This phenomena may have lead to the creation of the Clavecin Oculaire by the fellow Jesuit Louis Bertrand Castel, an early exploration of the relationship between pitch and colour. The Clavecine Électrique was well received by the press and the public but wasn’t developed further. The model Delaborde himself built survives and is kept at the Bibliothèque nationale de France in Paris.
The Clavessin électrique at the Bibliothèque nationale de France in Paris
The Clavessin électrique at the Bibliothèque nationale de France in Paris
Description of the Clavecin by Marc Michel Rey, 1759 in his "Le journal des sçavans, combiné avec les mémoires de Trévoux"
Description of the Clavecin by Marc Michel Rey, 1759 in his “Le journal des sçavans, combiné avec les mémoires de Trévoux”
(1) “The warning bell mechanism was based on an apparently unnamed method used in early electrical laboratories to audibly warn an experimenter of the presence of an electrical charge; it was probably invented by Andreas [Andrew] Gordon in Erfurt in 1741 and was described or demonstrated to Benjamin Franklin in Boston in 1746. An eight-bell instrument based on this principle was developed in about 1747 by Ebenezer Kinnersley, an associate of Franklin in Philadelphia, and the device subsequently received substantial publicity when it was mentioned in Franklin’s publication of his experiments with atmospheric electricity. Nearly 80 years were to elapse before the next sounds were produced by electricity.”
(Davis, Hugh.The New Grove Dictionary of Music and Musicians)


Collins, Nicholas. “Electronic Music”  , Margaret Schedel, Scott Wilson

Laborde, Jean-Baptiste de, “Le Clavessin électrique; avec une nouvelle théorie du mécanisme et des phénomènes de l’électricité”. Réimpression de l’édition de Paris, Guérin, Delatour, 1761. Genève, 1997. 1 volume in-16 de 192 pages, broché.

Schiffer, Michael; Hollenback, Kasy; and Bell, Carrie. 2003. Draw the Lightning Down: Benjamin Franklin and Electrical Technology In the Age of Enlightenment. University of California Press. ISBN 978-0-520-23802-2

“Le journal des sçavans, combiné avec les mémoires de Trévoux”, Volumes 45-46

“Dictionnaire des origines, decouvertes, inventions et …”, Volume 1  Antoine et Prefort Sabatier de Castres (l’abbe Bassin de), l’abbe Bassin de Prefort

“Les jésuites et la musique: le Collège de la Trinité à Lyon”, 1565-1762 Pierre Guillot

“Mémoires pour l’histoire des sciences et des beaux-arts”, Volume 236; Volume 1759