The ‘Synthetic Tone’, Sewall Cabot, USA, 1918

Patent documents of Cabot's Synthetic Tone Instrument
Patent documents of Cabot’s Synthetic Tone Instrument. Image United States Patent office.

The ‘Synthetic Tone’ was an electro-mechanical instrument similar but much smaller to the Choralcelo designed by the Brookline, Massachusetts electrical engineer Sewall Cabot. The instrument created complex tones by resonating metal bars with a tone-wheel generated electromagnetic charge.1Roads, Curtis,(1996) Early Electronic Music Instruments: Time Line 1899-1950, Computer Music Journal Vol. 20, No. 3 (Autumn, 1996), MIT Press, 20-23.

“One object of my present invention is to provide an improved musical instrument of relatively small cost and small dimensions in comparison to those of a pipe-organ, but capable of attaining all the musically useful results of which a pipe-organ is capable. Another object is to provide an instrument that will produce desirable tonal effects not heretofore obtainable from a pipe-organ.”2 United States Patent Office,#1705395

Sewall Cabot was a U.S. electrical engineer and an early (1906) contributor to the development of vacuum tube detectors before lee de Forest’s ‘Audion’ patent of 1912. 3 Cabot, Sewall, (1927) Detection—Grid or Plate, QST 1927-03: Vol 11 Iss 3, 30 Cabot was responsible for the later (1916) re-design of the Choralcelo electronic instrument.


References:

  • 1
    Roads, Curtis,(1996) Early Electronic Music Instruments: Time Line 1899-1950, Computer Music Journal Vol. 20, No. 3 (Autumn, 1996), MIT Press, 20-23.
  • 2
    United States Patent Office,#1705395
  • 3
    Cabot, Sewall, (1927) Detection—Grid or Plate, QST 1927-03: Vol 11 Iss 3, 30

 

The ‘Choralcelo’ Melvin Linwood Severy & George.B. Sinclair. USA, 1909

The keyboard manual of a Choralcelo installed in Denver Colorado. Photo Art Reblitz ca 1970.

The Choralcelo (“heavenly Voices” – pronounced: ‘Chor-al-Sello’) was a hybrid electronic and electro-acoustic instrument conceived as a high-end commercial domestic organ, aimed at wealthy owners of large country houses in the USA – houses large enough to accommodate the huge instrument. The Choralcelo was designed and developed by Melvin L. Severy with the assistance of his brother in law George B. Sinclair and manufactured by the ‘Choralcelo Manufacturing Co’ in Boston, Massachusetts. Later models were extensively redesigned and improved by Quincy Sewall Cabot, inventor of the ‘Synthetic Tone’.

Melvin Severy b.1863 Melrose, Mass; d. California 1951
Melvin Severy b.1863 Melrose, Mass; d. California 1951 
Severy was a prolific inventor (his patents included: printing presses, typewriters, solar heating systems, a camera, steam engines, fluid drives among many others) engineer musician, composer and author. The Choralcelo itself was a custom combination of the numerous electro-acoustic musical devices that Severy had designed since 1880 – electro-magnetic keyboard controls, tone generators and magnetic–acoustic string resonators 1“First Choralcelo Concert Proves Highly Successful,” The Musical Age (1 May 1909) . The first version of the Choralcelo was presented to the public on the 27th April 1909 at the Boston Symphony Hall, Boston, Mass accompanied by a soprano singer and forty members of the Boston Symphony Orchestra:

“First Choralcelo concert proves highly successful

As for the Choralcelo itself, it proved an interesting and unique instrument. Fronting the audience from the platform was a mahogany box to disguise an upright piano somewhat exaggerated, and with two rows of keys. The Instrument, it was announced, resulted from twenty one years of persistent labour on the part of it’s inventor Melville (sic) L. Severy and George D. Sinclair both of Boston. The Choralcelo obtains sound of the violincello, the trumpet and the French horn , the oboe and the bassoon, the harp and the pipe organ from a single compass from the wire strings used in the pianoforte, which are vibrated by means of small electromagnets stationed at scientifically determined points along their length.
The surprise in the Choralcelo is that the ordinary piano string can be made to give more sounds than those obtained from it under the blows of the hammer, and the variety of these sounds is great on the account of the immensely increased possibility of making what the student musician knows as overtone. The concert this evening faithfully demonstrated the merits of the Choralcelo, and it may be expected to contribute important things to music. Great skill is required in it’s handling. The player is embarrassed somewhat by the very largeness of the means at his disposal. He must learn to select. With careful study this new instrument is designed to do many and large things and the contention of it’s inventor seems to be fully justified” 2 The Musical Age. New York, May 1st 1909.
programme of the first Choralcelo concert, Boston, 1909.
programme of the first Choralcelo concert, Boston, 1909.
In 1915 The Choralcelo company was taken over by Wilbur Farrington and A. Hoffman (who, in some reports is named as its inventor). Sheets argues that by 1917 up to 100 of the instruments were produced 3Sheets, Arian, (2013) Choralcelo, Grove Music Online. Retrieved 27 Nov. 2021, from https://www.oxfordmusiconline.com/grovemusic/view/10.1093/gmo/9781561592630.001.0001/omo-9781561592630-e-1002240451.  At least six of the instruments are known to have been sold4Jenkins, C.W (2002) The Choralcelo, Amica Bulletin. AMICA International
Automatic Musical Instrument Collectors’ Association
and several  continued to be used up unit the 1960’s – no working examples have survived.
The Choralcelo was a direct contemporary of the Telharmonium, though not quite as large, was still a huge instrument and, for the organ section of the instrument, used a similar electromagnetic tone-wheel sound generation method as the Telharmonium combined with a set of electromagnetically operated and sustained piano strings.
The visible part of the Choralcelo consisted of two keyboards, the upper (piano) keyboard having 64 keys and the lower 88 (piano and ‘organ’), controlling the invisible part of the instrument, usually in the basement of the house, consisting of 88 tone wheels and a set of piano strings and bells that were vibrated by electromagnets and a set of hammers. The keyboards also had a set of organ style stops to control the timbre and fundamentals of the tone that could then be passed through cardboard, hardwood, softwood, glass, steel or “bass-buggy” spring resonators to give the sound a particular tone.The Choralcelo also incorporated a pianola style paper roll mechanism for playing ‘pre-recorded’ music and a 32 note pedal board system. The entire machine could occupy two basements of a house, the keyboards and ‘loudspeakers’ being the only visible part of the instrument.

Sounds of the Choralcelo

“Poor Little Butterfly” from an original 78rpm glass master live 1942 recording, hand played by Regene Farrington, wife of Wilber Farrington, President of The Choralcelo Co. Recorded in the Choralcelo Studio in New York City. (from: C. W. Jenkins, AMICA)

Promotional brochure from the  Choralcelo Manufacturing Co

Detailed History of the Choralcelo from “History Of the Choralcelo” by W.Jenkins

“The information furnished is based on forty years of acquaintance with the instrument, and on three complete Choralcelo instruments at hand, friendship with one of the principals, interviews with others involved in the work, family members, original blueprints, all the patents issued, (and there were many) and original documents from the archives. “

“The story of the Choralcelo is largely the story of two men… Melvin L. Severy, born in 1863 in Melrose, Mass; died in California in 1951; and Wilber E. Farrington, born 1869, died 1945. Severy was a brilliantly gifted, multi-faceted inventor who secured patents on a printing press, solar heating, a camera, fluid drive, and many others, besides the Choralcelo. He was a scholar, artist, musical composer, and author. His grandson recalls that he was interested in secret passages in the pyramids, to name one of his many interests. Severy was assisted in his experimentation by his brother-in-law, George B. Sinclair. They had married Flint sisters. Wilber Farrington was an idealistic, philosophic visionary who devoted the majority of his life to his love of the unique tone of the novel instrument and his determination to see it successfully developed and manufactured. He was a charismatic and effective fundraiser and invested his own fortune in the work.There had been many efforts at strengthening or lengthening the tone of piano strings electrically.

Remains of a Choralcelo at the National Music Museum, Vermilion Sands, South Dakota
Remains of a Choralcelo at the National Music Museum, Vermilion Sands, South Dakota

As early as 1876, Elisha Gray had patented a single note oscillator; and in 1890 Eli C. Ohmart filed a patent on prolonging the tone of piano strings electromagnetically… the patent was assigned to Melvin Severy. The principle being worked on was simple… magnets were placed behind the strings of the piano, and accurately timed pulses of DC current were fed to the magnets coinciding with the natural periodicity of the strings.. for example, if note A vibrated at 440 vibrations per second, then 440 pulses of current per second would be fed to the magnets for that note, and sustained organ-like tone would be produced without the use of the hammers. The mechanism which accomplished this was the interruptor, powered by a small electric motor, which had nine brass cylinders 3 1/2″ long spinning at predetermined speeds. Each cylinder had eight make and break tracks 1/4 inch wide, alternate spaces being set in an enamel, a non-conductor. Sterling silver brushes rode on these tracks. The lowest notes required about 20 pulses per second, and the highest, about two thousand. The overwhelmingly difficult part was the governing of this device… the very slightest deviation and the frequency of the pulses would not coincide with the natural periodicity of the strings, and the tone will die. Patent after patent was filed for variations on governing mechanisms, some of them so elaborate that they were complicated mechanisms in themselves.

The basic concept of tone production, though simple, proved nearly impossible in execution… matching, on one side, an already tuned vibrating body, with perfectly matching pulses of magnetism, ranging anywhere from 20 vibrations per second to 2,000. The governing device controlling the speed of the make and break cylinders would not only have to provide such absolute perfection whenever called for, but would also have to be able to compensate for the vagaries of the electric current generated in that day, which powered the motor the drove the governor… to do this, it would have to be able to keep the cylinders rotating without the slightest deviation even if the motor driving the assembly slowed down or speeded up. If the speed of the cylinders changed while the instrument was being played, the tone would die out.

Remains of a Choralcelo at the National Music Museum, Vermilion Sands, South Dakota
Remains of a Choralcelo at the National Music Museum, Vermilion Sands, South Dakota

An elegantly simple, brilliant magnetic combination governor and clutch evolved, which performed perfectly without physical contact, so there could be no overheating, and there were no clutch pads or other friction assemblies to wear out. Even today it is a marvel of brilliant application of principles of physics , and a marvel at least to those who are aware of what they are seeing to watch the spinning copper band drive the heavy flywheel merely by cutting through the invisible magnetic force. It is so disarmingly simple one could have no inkling of the years of labor which preceded it. Appreciating what it represents, I still have a feeling of awe. I doubt there has ever been anything like it, before or since. It was through the many mechanisms Severy laboured over and patented in his determination to solve the problem that fluid drive evolved. The first concert was given in 1905, and was by invitation.

The Choralcelo of that first phase of development was an impressive upright piano with one keyboard, usually with a roll player; the case of the finest grain mahogany with beautifully hand-carved openwork scroll panels. The tone could be varied by means of a slider near the left hand. It was the first tone produced without physical contact of some kind, and the tones produced invoked orchestral instruments minus the sound of the bow on the string or the breath of the flutist.

cc_48

Development continued and a two manual instrument marked the second level, or phase, of the evolution of the Choralcelo. It still had the piano keyboard and piano strings which were excited by magnets. The piano strings were tuned by means of screws to attain greater stability. There was an organ keyboard above the first one, and a row of stops to control the range of tone units. These took the form of sets of tuned bars, or plates, which could be of steel, or wood, or aluminium, or sometimes glass. There were usually 41 to a set, and typically they varied in length from 5 3/4″ to 10 1/2″, and usually were about 5/16″ thick. Materials other than steel had small iron armatures affixed so that there would be response to the magnets.

choralcelovig

Installed directly over these bars were resonating chambers, usually cylindrical fiber tubes, open at each end, which reinforced the tone, just as one sees in marimbas and vibraharps, The tone production was entirely acoustic; there was nothing electronic about the Choralcelo… no amplifiers, no loud speakers, no tubes… nothing of the sort. These sets of bars were remote from the main console and could be placed anywhere. The switching and control devices were remote from the main console and could be contained in two cabinets, each about 5 1/2′ high, and installed in the basement, along with the interrupter mechanism and motor-generator which delivered 30 volts of DC. The bar units could also be installed in the basement if desired, in which case grillwork was installed in the floor above them to transmit the sound; or they could be installed in the music room where the console was and concealed behind panelling or whatever was desired. The units were all connected by cables, usually armored with interwoven wire strands to protect them from damage. If all the machinery and also the bar units were to be placed in the basement, the space required would be approximately that of a modest bedroom.

Melvin L Severy circa 1915
Melvin L Severy circa 1915

The final phase of the development of the Choralcelo was the rewiring of the controls so that upper partials could be at the command of the Choralcelist and thus the potential of the instrument was greatly expanded because infinite variations and combinations were now available. The attempt to produce a completely new, unique instrument of this complexity in such a short period of time… the original factory closed in 1917 because of the war… was a monumental undertaking, and the multiplicity of the directions one might take was daunting. After all, the piano metamorphosed over several centuries, and other instruments have done the same. Experiments were conducted with reeds. A magnificent, large double bass unit having steel ribbons instead of individual strings was developed… there was a remote full-sized string unit which could be remotely placed… A variation of the interrupter mechanism was developed using brass discs instead of the earlier cylinders. There were twelve discs, each with six tracks, rotating at speeds determined by the gearing. All of these inventions, some of which were superseded by later ones, required designing, engineering, machining.. the investment was astronomical. In today’s money it amounted to many hundreds of millions of dollars. The instruments themselves were expensive, by today’s standards costing about a half million.

There were about one hundred built, many of them being installed in the music rooms of the wealthy. There were some that were in theatres to accompany silent films… Filene’s in Boston had two, one in the restaurant. Lord and Taylor in New York, and Marshall Field in Chicago, among others, featured Choralcelos, as did several hotels. There were even two on yachts.

The effort was a daunting task but great strides had been made by the time WWI broke out… materials were no longer available and as a result, the factory closed. Farrington and several of the most devoted men involved remained active in several locations, Cleveland, Chicago, Port Chester, Connecticut, and New York among them. The last activity was a demonstration studio in New York City, but another world war broke out and the studio closed in 1942.”

Choralcelo Patent Files

‘The Choralcelo, a Wonderful Electric Piano’

 ‘The Electrical Experimenter’ Magazine, USA. March 1916

This Marvelous Electrically Operated and Controlled Musical Instrument is More Than a Piano – It Produces Sustained Notes of the Lowest and Highest Register, Over a Range Heretofore Unattainable, and, Moreover, is Played Like a Regular Piano

In India, far away, as the popular song goes, the natives are content to regale themselves musically with plaintiff notes given forth by a goat skin stretched over the end of a hollowed log, upon which the musician beats a tune with the flat of his hand.

The music of the caveman was the wind is sighing through the trees, accompanied by the rustle of the leaves. Even they wanted to express themselves in a harmonious manner, hence the drum, the horn and other crude instruments of musical expression.

Then we may possibly expect some marked advances in our musical culture and education since the advent of the “Choralcelo,” despite the prophecies of those who take a pessimistic view of life in general.

The piano becomes a tongue-tied infant beside the latest masterpiece of the musician’s art. At times its notes thunder forth and seem to shake the very earth itself, and then again they may be subdued to an elusive softness like unto the faint notes of a distant church choir.

But what is it? How is it accomplished? What is the result of many years of untiring labor on the part of several of the cleverest men of the world? What is it upon which a fortune that would ransom a king has been spent? The Choralcelo!

The Choralcelo, the most wonderful musical instrument ever thought out by the human mind, is like nothing else the world of music has ever known. This masterpiece reproduces any piece of music in any form of instrument, from a string to a flute; not only does it reproduce them, but the notes emitted by it are sustained, pure and sweet, which is entirely different from the ones produced by the instruments that are in present use.

Practically all the musical instruments, previous to the invention of the Choralcelo, carry into the tone which they produce certain impurities which arise from the manner in which they are caused to vibrate. The violin interrupts the free vibration of the string by the grating rub of the bow. The piano adds the noise that results from the blow of the hammer on the string – while the organ mingles the breathiness of its air current with the pure vibrations of the column of air in the pipe. In like manner all instruments employing extraneous contacts to start the vibration destroy the purity of the note produced. And as they seek to amplify the tone they have produced they increase the intrusion and false sounds. The soft pedal of the piano, the swell-box of the organ, the mute of the violin, are just so many outrages on the purity of the tone.

The Choralcelo, by the very means which it employs in producing the tones, is freed from all obstructions. Vibration without contact, involving perfect freedom of vibration, and thus the Choralcelo gives all the natural overtones and harmonics; rich – full – pure and perfect, thus opening to the musician wonderful possibilities of expression and emotional power of which he possibly never dreamed.

The manner in which this result is accomplished is one of wonder. It is the subtle pull of the electromagnet which now achieves pure tone production. These electromagnets are caused to act directly upon the strings of the instrument.

The most delicate graduation of tone power can be produced by the mere variation of the strength of an electric current, and not by smothering devices which the present form of instrument employs. The tone, therefore, retains all its original purity through all vibrations and intensity, something that has been impossible heretofore.

We will next inspect the mechanism employed to perform these wonders. It may be stated that the vibrating elements are caused to oscillate by means of a pulsating electric current sent through an electromagnet acting on the vibrating membrane.

The machine which beaks up continually the electric current into a series of waves is really the “heart” of the Choralcelo. The operating device consists essentially of a series of metal discs having a certain number of insulating segments inserted into their peripheries. These discs are arranged to revolve at a fixed speed. Silver-tipped brushes are so placed that they will bear upon the revolving discs. It will thus be seen that in order to produce the fundamental periodicity of any given “string”, it is only necessary to rotate a disc containing a certain number of segments at the correct speed.

A large number of combinations are possible through the manipulation of a few keys, which correspond to the stops of an organ, and such a keyboard is clearly shown at Fig. 1. This resembles a piano, and it really is one, with additional keys and pedals. The pedals are used to vary the strength of the current sent through the electro-magnets.

A tremolo effect is given by means of a slow speed interrupter giving a pulsating current at a few revolutions per second. The instrument which produces this effect is depicted on the right of Fig. 2, while the one towards the left reproduces tones representing a flute. The regulation piano tone is produced with the usual percussion hammers, which may be thrown into or out of action by the pressure of a key. The staccato notes of the piano may be struck upon strings already vibrating with the pulsating current. Thus sustained notes of a higher pitch are produced upon the string.

A piano which employs both the electro-magnets and hammers is clearly shown on the left of Fig. 3. Note the large number of wires which are employed for connecting the various for connecting the various magnet coils. It is an engineering feat in itself to even make and wire the various circuits.

Marvelously sweet tones are produced by vibrating pieces of brass, wood and aluminum. In fact, any resonant body susceptible to vibration may be made to emit tones. In order to cause these bodies to vibrate, it is necessary to place within them a small piece of iron, so that the electro-magnets may attract them. Instruments that are operated by this method are depicted in Fig. 3. The one toward the right is an instrument that imitates a flute. The electro-magnets are placed underneath the tubes, which are made out of wood and act as resonating chambers. The magnets are caused to act on iron discs mounted at the lower end of the tube. Another style of flute instrument is illustrated in Fig. 4. This employs a different variety of tubes, ranging from a very high tone to a very low one. The smaller pipes give the latter tone, while the larger ones the former.

The instrument shown in the center of Fig. 3 illustrates a brass chime. The tones are produced by hammers, each of the tubes being supplied by one. These are operated by electro-magnets, as perceived in the upper bracket of the stand. These are also connected to the same keyboard.

The very deep tones of an organ are produced by vibrating diaphragms placed beneath metal horns. A pair of electromagnets are held a minute distance away from the diaphragm and serve to vibrate the latter when the pulsating current is applied. The volume of the tones is powerful and is very pleasant although it is very low. By increasing the power in the electro-magnets, the strength of the tones is so much increased that it is almost impossible to imagine the effect.

“Echo” combinations may also be installed without limit wherever their effect may be most beautiful at any distance from the master instrument. Thus the greatest cathedral may be filled with a glory of sound. The tower may be used to flood the surrounding country with the same divine melody. It may also be carried to the quiet cloister and to the private room. An instrument played in one place may repeat its music elsewhere.

The Choralcelo was developed and its wonderful basic principle discovered by Melvin L. Severy of Arlington, Mass., and George B. Sinclair. These savants have been working for twelve years to bring this musical instrument up to the perfection which it has reached today. One cannot predict its possibilities or limits as it is really still in its early stages of development. 5‘The Choralcelo, a Wonderful Electric Piano’
‘The Electrical Experimenter’ Magazine, USA. March 1916


Sources

  • 1
    “First Choralcelo Concert Proves Highly Successful,” The Musical Age (1 May 1909)
  • 2
    The Musical Age. New York, May 1st 1909.
  • 3
    Sheets, Arian, (2013) Choralcelo, Grove Music Online. Retrieved 27 Nov. 2021, from https://www.oxfordmusiconline.com/grovemusic/view/10.1093/gmo/9781561592630.001.0001/omo-9781561592630-e-1002240451.
  • 4
    Jenkins, C.W (2002) The Choralcelo, Amica Bulletin. AMICA International
    Automatic Musical Instrument Collectors’ Association
  • 5
    ‘The Choralcelo, a Wonderful Electric Piano’
    ‘The Electrical Experimenter’ Magazine, USA. March 1916
H.Trabandt: ‘Das Choralcelo’ ZI,xxix (1910)-‘Das Choralcelo als Konzertinstrument’ ZI xxx (1910)

http://www.amica.org/Live/Publications/Past-Bulletin-Articles/Choralcelo/index.htm

http://www.amica.org/Live/Publications/Past-Bulletin-Articles/Choralcelo/cc_61.htm

Amica Bulletin. Volume 45, Number 4 August/September 2008

The New England Magazine.

‘An Early Electro-Magnetic Experiment’ Edith Borroff, College Music Symposium Vol. 19, No. 1 (Spring, 1979), pp. 54-59