Although perhaps the first electrical music synthesizer, Cahill's innovation, generally known as the Telharmonium, proved to be impractical. The major complaint was that the generated signals were so stong they caused interference to adjoining telephone lines, which meant that regular phone users found their conversations accompanied -- or drowned out -- by the music.
The World's Work, June, 1906, pages 7660-7663:




ALTHOUGH electricity has produced many wonders, they have been mainly of the workaday kind. Now an invention has been wrought out that proves that electricity is capable of producing--not reproducing, but producing--music of rare beauty and purity. A visit to a shop in Holyoke, Mass. shows a machine that is really manufacturing music.
    Dr. Thaddeus Cahill, the inventor, declares that it is as easy to create music at the other end of fifty miles of wire as to send a telegraph message. At a keyboard of his device a performer--or there may be two--lightly presses down the keys, and at receivers, perhaps many miles distant, music pours forth. In pressing the keys the performer throws upon a wire a vibration--or a set of vibrations--which turns into aerial vibrations or audible music, when it reaches the diaphragm of a telephone receiver. The vibrations stand for notes and tones, and they scurry along to do their work the instant they are released. The performer is conscious only of the music he produces. He does not necessarily hear it.
    He need know nothing of the mechanical process he sets in action by the pressure of his fingers on the keys. Yet under his fingers the electrical vibrations act tractably and instantaneously. At will he turns an exhaustless supply of different kinds of vibrations to produce at a distance just the sounds he desires.
    Only those wise in electrical knowledge will ever understand just what has taken place in the Cahill laboratory, but in bare outline it is this: An alternating-current generator has been built up for each note of the musical scale. Each of these generators produces as many electrical vibrations per second as there are aerial vibrations per second in the note of the musical scale for which it stands. From the generators a mass of wires leads to the keyboards. The keys operate switches which conduct the desired vibrations from the generators, much as in a pipe organ the player, by pressing certain keys, turns the air from the bellows into different pipes to produce the tones he desires. These vibrations are passed through several transformers or tone mixers to become still more complex, and then the interwoven vibrations go forth on a wire.
    Although the process seems involved, the action is instantaneous. The performer presses the key which sets in motion a set of electrical vibrations, corresponding to a note, and in a thousandth of a second the note sounds with perfect distinctness and purity from the receiver, whether it be at the performer's elbow or many miles away.
    In the music room where the performer sits, there would be absolute silence, if it were not for the receiving horn placed near him, so that he can judge of the character of his playing. The vibrations do not turn into sound until they reach the telephone receiver. Yet the wires all the time are full of silent music, which could be distinguished if the ear were constructed to catch electrical vibrations as it is to catch aerial vibrations.
    In a small dark room close by the music room is a long box in which are 400 telephone receivers attached to the instrument but with their noses buried in sawdust so that their voices are silent. If a handful of them are dragged out of their sawdust bed, however, they sing out loudly on the air. The wires between the instrument and the receivers may be tapped anywhere to give forth musical sounds, and when Dr. Cahill completes his system, he may literally fill the world with a network of music.
    The possibilities of this new musical instrument are almost limitless, for not only can it produce the tones of almost all the known orchestral instruments, but it creates musical sounds never heard before. The tones of the different orchestral instruments are secured by mixing with the ground tone one or more harmonics in the required proportions. For instance, at a touch of the third and fourth of the harmonic stops, which are located above the keyboard, something in the manner in which organ stops are arranged, the performer may change a flute-like note to the sound of a clarinet, or, by using all the harmonics up to the eighth, the tone may be transformed into a string sound. Another combination of harmonics gives the strident sound of brass. As a final triumph a musician can so combine the harmonics as to produce musical timbres unknown before. He may develop an almost limitless number of new sounds according as his patience and his soul direct. Electrically he produces the different musical timbres by mixing vibrations of different frequencies. The effect of a full orchestra is brought about satisfactorily when two players are at the key-board.
    One of the most remarkable features of the device is the delicacy of control. It lends itself instantly to expression, and responds more sympathetically to the soul of the musician than any other instrument, with the exception, perhaps, of the violin. It is as sensitive to moods and emotions as a living thing. The performer by a mere touch controls the various shades of the notes, and varies them at will. The three musicians who are perfecting themselves in the mastery of the instrument at the Cahill laboratory, find to their delight that all the varying meanings and emotions of classical music may be brought out artistically.
    To play electrical music a performer must have some knowledge of the piano and must be a thorough musician. So delicate is the instrument that listeners at a receiving station many miles distant may detect the difference in touch of the players. A Bauer or a Paderewski at the instrument could delight an audience ten miles distant as thoroughly as if the listeners were in the concert hall with the musician. The keyboard has two banks of keys, a row of stops to regulate the harmonics, and a few other devices which help to determine the expression. But there is not a pipe, a string, or a reed in the entire apparatus. Everything is electrical.
    At the receiving stations the device is simply a telephone receiver attached to a large horn, like that of a phonograph. The telephone receiver may not be held to the ear, for the current is so strong that its effects would be injurious. For, whereas a current of only six ten-millionths of a millionth of an ampere is sufficient to produce a sound in an ordinary telephone receiver, in the Cahill system a current of an ampere is sometimes used for an instant for loud tones. In consequence of the strength of the current, the musical tones are not marred by any of the noises along the line such as oftentimes seriously disturb the feebler current of the ordinary telephone.
    The invention is not in the experimental stage. The first commercial installation has been completed. The second is being constructed and will probably be placed in New York City as a central station for distributing music. The machine already finished is a massive device of metal and wires. It weighs more than 200 tons and cost $200,000. There are 145 of the alternating generators grouped in eight sections and the switchboards, including nearly 2,000 switches, are in ten sections. Music was sent successfully from Dr. Cahill's original laboratory to New Haven, a distance of 70 miles over a leased wire. In a Holyoke hotel, a mile distant from the central installation, where two receiving horns, have been stationed, a large ballroom is filled with the music. There is none of the rasp and harshness of the phonograph about it; its tones are pure, clear, round, and rich. By the very nature of the mechanism the instrument is permanently tuned.
    The most important feature commercially of the electrical music is that it may be produced simultaneously in thousands of places many miles apart with as much power as if an orchestra were in every one of the places. Several of the generators for single notes send out from 15 to 19 horse-power. Notes with several horse-power behind them naturally have no difficulty in supplying many receiving stations at once. All that is necessary to release the music at a receiving station is the moving of a tiny switch.
    Dr. Cahill plans to place the system at first in theatres, concert halls, restaurants, hotels, and department stores, but later he expects it will come into private use. In small towns where fine music is rarely heard a connection could be made with private homes from the central station in a large city and the masterpieces of music could be heard at will. The electrical music will go over its own wires and not over leased wires. Central stations will probably be not more than fifty miles apart, in order to get the best results. There will probably be operators or performers at the central station for twenty-four hours, and music will be on tap all hours of the day or night. An individual may go to sleep to music or rise to it according to his temperament, and a hostess may furnish an orchestra for her dinner party at the turn of a button. As the system develops, Dr. Cahill is hopeful that in due time there may be four sets of mains fed from the central station, each with a different kind of music, and by connecting the four sets of mains to a public place or a private home, rag-time ditties, classical compositions, operatic, or sacred music may be turned on according to one's mood.
    Dr. Thaddeus Cahill, the inventor, is a native of Iowa, but passed most of his youth in Oberlin, O., where he began his experiments with electrical music. Since 1889 he has lived at Washington, D. C. In 1892, at the age of twenty-five, he graduated from the Columbian Law School in Washington, the third in a class of more than a hundred. He was admitted to the bar in 1894, and in 1900 received the degree of D.C.L. from the Columbian University. The study of law, however, did not dampen his ardor for scientific studies, and in the nineties he worked out his musical apparatus to a degree of perfection. In 1903 he removed his laboratory from Washington to Holyoke, where he has since been engaged in building the large machines as well as in perfecting and improving various details.
    The machine here illustrated is the one built by Dr. Cahill at Washington. It has a special interest as being his first complete machine and the first apparatus ever used to generate music by means of alternators. He built it in the late nineties, experimented with it for several years, and had the satisfaction of exhibiting it to Lord Kelvin at Washington in April, 1902.