Electrical Experimenter, April, 1919, pages 855, 924:

Grand  Opera  in  Your  Home

MANY thousands of people musically inclined are deprived of hearing our great operatic stars mainly on account of the high price of admission, also because of the limited seating capacity of even our largest opera houses. Take for instance a "star" performance at the Metropolitan Opera House, New York City. It is necessary to secure tickets weeks ahead if one wishes a good seat in the house, otherwise it is often impossible to make a reservation at all.
    While seats may be bought at low prices "up in heaven", only our Italian friends of limited income prefer such seats and, therefore, the gallery is usually made up entirely of really music-loving Italians.
    Suppose that all you had to do was to step to the telephone at 8.30 in the evening, no matter if you lived in New York or anywhere else in the country, and immediately had the whole room filled with Caruso's voice. Would this not appeal to you, providing of course that you were musically inclined? All this is now possible, and, we believe, will shortly come about. While of course the idea itself is nothing new--it having been tried thirty years ago to transmit music in this manner,--there was one great technical difficulty at that time which only during the past two years has been overcome.
    While it is a comparatively simple thing to place sensitive microphones about the stage and on the other end of the line connect a loud speaking telephone in order to listen to the transmitted music, it is quite a different problem to connect say twenty or forty thousand subscribers' lines to these microphones and then reproduce the music at the end of all these thousands of circuits. The reason is that heretofore we had no satisfactory instrument whereby the microphone circuit could be loaded simultaneously with such an immense number of lines which practically constitutes a short circuit, and while the thing is possible in a limited way by means of induction coils, not more than two or three hundred subscribers could be linked up by such means. Therefore, the system heretofore was a failure.
    The invention of the Audion, however, has changed this and by using audions to "boost" the circuits, it is now possible to connect a practically unlimited number of lines to one microphone transmitter and reproduce the music clearly in 50,000 homes at the same time.
    The writer who interviewed high telephone officials was informed that the plan was entirely feasible and there was only one objection, which is not of a technical nature but rather a commercial consideration. Thus, the telephone engineers did not think it good business to tie up say twenty thousand to fifty thousand lines simultaneously for several hours at a time on account of the congestion that would probably ensue, but this is really only small consideration and not of much importance if the enormous revenue that the companies will derive from this scheme is taken into consideration. While the subscribers now pay only between two and five dollars a month for service on an average, the telephone company could easily double this revenue for at least 20 per cent of all of their subscribers by installing the operatic service.
    Today the man who owns a phonograph thinks nothing of spending between three to five dollars a month for records which are "dead". If he knew he could hear Caruso, Galli Curci or any of the other stars tonight in one of his favorite operas, he certainly would not object to spending 50 cents or even a dollar for the privilege, and at that he would think he was getting it cheap because he, with his entire family, would hear the music in his own home without having to travel to and from the opera. Of course, if the system eventually comes into vogue, the opera alone will not be the only source of amusement to be drawn up by a telephone subscriber. Any of the musical shows or comedies, farces, etc., could all be heard over the telephone, altho admittedly not to such an enjoyable extent as grand opera, where it is the music that counts most.