Review of Reviews, April, 1906, pages 420-423:

telharmonium
THE  TELHARMONIUM:  ELECTRICITY'S  ALLIANCE  WITH  MUSIC.

BY  THOMAS  COMMERFORD  MARTIN.
IN the new art of telharmony we have the latest gift of electricity to civilization, an art which, while abolishing every musical instrument, from the jew's-harp to the 'cello, gives everybody cheaply, and everywhere, more music than they ever had before. There are so many fundamental and revolutionary ideas embodied in the invention that it will be a long time before we grasp or grow accustomed to them all and only one or two can now be accentuated. Electricity has been the greatest centralizing, unifying, force these hundred years, and the "tie that binds" is distinctively made of wire. The art of telharmony pushes one degree further the dominant principle of current-production embodied in the telegraph office, the telephone exchange, the electric-light plant, and the trolley power-house ; and it emphasizes just a little bit more the practice of drawing out from the circuit, at the point of consumption, just what is needed for intelligence, communication, illumination, heat, traction, and what not. For such service the American people spent, last year, one billion dollars, and now it is going to add its music bill to that modest sum, because there will be economy and gain in it. Thaddeus Cahill

ELECTRIC  WAVES  OF  MUSICAL  SOUND.

    That the sounds of music can be transmitted over a line wire is nothing novel. In a rudimentary way, the systems of harmonic telegraphy based on tuned "reeds" point the way ; and the very earliest work in telephony in Europe and America dealt rather with music than with speech. Many of us have laid our ear-flaps over a telephone receiver and listened to music transmitted from a distant opera house or concert hall or church ; and some of us have even seen a rollicking phonograph cylinder, in New York, sing songs and "A Life on the Ocean Wave" with the purpose of dispelling the dull gloom in distant Philadelphia. All of this was excellently well ; but in each instance the music received and delivered came, triturated and emasculated by the trip, from an instrument. In the Cahill telharmonium we have changed all that, and we enter a pure democracy of musical electrical waves from among which, at will, those that please us best can be selected, to give us any tune or tone or timbre that we want.
    This all reads wildly extravagant, but it is the cold statement of a bald fact. The new system of telharmony has need neither of sounding brass nor of twanging string. Whether piano, violin, pipe organ, or flute, all are alike and indifferent to it, because along time lines that Helmholtz laid down, and that the foremost electrical invention of our time has been following, Dr. Thaddeus Cahill has devised a mechanism which throws on to the circuits, manipulated by the performer at the central keyboard, the electrical current waves that, received by the telephone diaphragm at any one of ten thousand subscribers' stations, produce musical sounds of unprecedented clearness, sweetness, and purity. In the future, Paderewskis will not earn their living by occasional appearances in isolated halls, but as central-station operators, probably in obscurity and seclusion, but charming a whole cityful at the same instant. Edison once said to the writer that the world was coming to a time when everything would be done automatically, by electricity, and when "eight hours" would seem the depth of slavery. Then the world would be run from one keyboard ; but while all others loafed and invited their souls he wanted to be the man at the switch. In this wise, when Liszt or Rubinstein is at the telharmonium, what will become of the second-rates? alternators

PLAYING  UPON  THE  CURRENT.

    The Cahill telharmonium may be compared with a pipe organ. The performer at its keyboard, instead of playing upon air in the pipes, plays upon the electric current that is being generated in a large number of small dynamo-electric machines of the "alternating-current" type. These little "inductor" alternators are of quite simple construction, from the mechanical standpoint, though it is needless to say that the inventor did not find out at once all he wanted to know about them. That took a good ten years. In each alternator the current surges to and fro at a different frequency or rate of speed,--thousands and thousands of times a minute ; and this current as it reaches the telephone at the near or the distant station causes the diaphragm of that instrument to emit a musical note characteristic of that current whenever it is generated at just that "frequency" or rate of vibration in the circuit. The rest is relatively easy. The revolving parts of the little alternators are mounted upon shafts, which are geared together. Each revolving part, or "rotor," having its own number of poles, or teeth, in the magnetic field of force, and each having its own angular velocity, the arrangement gives us the ability to produce, in the initial condition of musical electrical waves, the notes through a compass of five octaves.
    When an organ is played, a boy, or now quite often an electric motor, pumps the bellows. When the telharmonium is played, a motor similarly sets it going, so that all the little interlocked rotors are revolved at once and offer their plastic currents to the facile touch of the performer to whose keyboard the wires from the alternators lead. This keyboard is shown in one of time engravings, and has two banks of keys to accommodate all the notes thus made available. If one key is depressed, the circuit is closed on a ground tone and one or more allied circuits that will give the harmonics corresponding to that tone. But the currents, before they go to the exterior circuit containing the subscriber's telephone are not left in their primitive simple form. On the contrary, they are passed, as they might be in ordinary lighting and power service, through transformers, where they are blended ; and in these "tone mixers" the simple sinusoidal wave of the alternator current becomes too complex to know itself. In this manner highly composite vibrations are built up which fall upon the ear as musical chords of great beauty and purity of tone. This process of interweaving of currents can be pushed very far, and the complex vibrations from different keyboards can be combined into others even more subtly superposed and wedded so as to produce in the telephone receiver the effect of several voices or instruments Within the range of such an equipment appear possible some sounds never before heard on land or sea.
    The performer at this keyboard has a receiver close at his side, so that he can tell exactly how he is playing to his unseen audience ; and it is extraordinary to note how easily and perfectly the electric currents are manipulated so that with their own instantaneity they respond to every wave of personal emotion and every nuance of touch. It is, indeed, this immediateness of control and the singular purity of tone that appeal to the watchful listener. A musician will readily understand how the timbre is also secured from such resources, for with current combinations yielding the needed harmonics, string, brass, and wood effects, etc.; can be obtained simply by mixing the harmonics,--that is, the current,--in the required proportions. tone mixer

THE  EQUIPMENT  DESCRIBED.

    The first plant in the world of this kind is at Holyoke, Mass., in the laboratory of Dr. Cahill, and the second is being built for regular work over telephone circuits in New York City, where anybody can tap on. The initial or experimental outfit, weighing about 200 tons and costing a thousand dollars a ton, embodies 145 of the inductor alternators, each mounted on an 11-inch shaft ; and the heavy steel girder bed-plate of the machine is over 60 feet long. The alternators are grouped in 8 sections, and the switchboards are in 10 sections, including nearly 2,000 switches ; and the controlling keyboard operates electro-magnetically. Then there are the inductorium "tone mixers." Altogether, quite a dainty little pile of steel, copper wire, and other metal out of which to extract soft music! But it does not follow that later equipments will necessarily be so ponderous. Moreover, the current-consumption in each telephone receiver of the megaphone style is infinitesimal. A single incandescent lamp takes twenty times as much ; so that a very few horse-power go a long way in the new art of telharmony.
    Such music can obviously be laid on anywhere,--in homes, hospitals, factories, restaurants, theaters, hotels, wherever an orchestra or a single musician has served before, or wherever there is a craving for music. The dream of Bellamy in "Looking Backward" is thus realized, and beautiful music is dispensed everywhere for any one who cares to throw the switch. The music from these electric pipes of Pan may the long list of obsolete instruments. Will the piano join the spinet and harpsichord? Who now shall need to strum?

DR.  CAHILL,  THE  INVENTOR.

    Dr. Cahill was born in Iowa, and passed several years of his youth in Ohio, his father being a physician at Oberlin, where the youth pursued his studies and began his experiments in electric music. Through the friendship of the late Amos J. Cummings, he obtained a clerkship in Washington, and there he began the study of law. In 1892, when twenty-five years of age, he graduated from the Columbian Law School, third in a class of over one hundred, and was admitted to the bar in 1894, receiving six years later the degree of D.C.L. from the Columbian University. The thoroughness of his legal work did not, however, in any degree lessen his enthusiasm and application as to invention and the study of musical production ; and he was fortunate in enjoying in all his work the constant and generous encouragement of his father and brothers. Although finding time to perfect an electric typewriter, he directed his chief attention to the musical apparatus, and in 1902 had it in a sufficiently advanced state to give a demonstration before Lord Kelvin when that distinguished physicist was last in this country. In 1903, Dr. Cahill removed his Washington laboratory to Holyoke, Mass., where he had already established another plant, and thus New England, so intimately associated with the creation of the telephone, has witnessed the development and perfection of a distinct new art that may well be spoken of as the telephone's firstborn.