While Theatre Organs appear to be an outgrowth of the Symphonic organ movement of the early 1900's, the first musical devices used to accompany early silent films were the piano and live orchestras. The theatre organ can really be said to have entered the picture on a tangent that was brought on by the economic limitations of having full-time orchestras in movie theatres. Some early theater owners recognized that the orchestral character of an organ could be put to use in accompanying films. Several church organ firms began to build church-like instruments that were modified for entertainment use. Many of these early theatre organs were actually trackers.

During this early development of the movie house organ, Robert Hope-Jones had been experimenting with large scale electrically controlled pipe ranks and sound effects for his concert hall instruments. Seeing a need for a device that could replace an orchestra in a movie theatre, Hope-Jones set out to perfect the "Unit Orchestra", an organ-like device, but with the distinction of having pipe work that was more representative of an orchestra than a church organ. Jones added sound effects to the instrument, and soon he found a market for his invention in the factory of one Rudolph Wurlitzer. Wurlitzer's company made pianos, music boxes and other musical instruments. Hope-Jones was given the task of filling orders for unit orchestras to be installed in a succession of grand, and not-so-grand movie palaces being built across the nation and in Great Britain.

Hope-Jones was an emotionally unstable eccentric who did not have a head for business, although he was probably one of the great engineers of his time. He perfected and patented many organ-related inventions during his tenure with the Wurlitzer firm, but his business practices placed him constantly at odds with the management at Wurlitzer. After some years of employment, and a lot of money lost on the part of the Wurlitzers, he was discharged for failure to meet the company's contractual obligations because of his inability to get instruments installed on time and on budget. As a result of this final rejection, coupled with a number of previous business failures and emotional struggles in his personal life, Jones committed suicide by inhaling gas from the gas jet in his apartment.

Wurlitzer managed to recover and maintained its position as the primary builder of theatre organs well into the 1930's. A number of other companies also built theatre organs, including Robert Morton Company, W.W. Kimball, Barton (Bartola Musical Instrument Co.), Marr and Colton, Wicks and a host of others including some established church and symphonic organ builders.

The question is often asked as to what are the primary differences between church organs and theatre organs. The differences are distinct in that:

1. Theatre organs usually operate at higher pressures and volume levels than do church organs

2. Theatre organs usually have faster and deeper tremulants

3. Theatre organs are usually equipped with sound effects including real percussions, drums, bird calls, klaxon horns, sirens, and things the listener really does not want to hear during the average church service.

4. Most importantly, theatre organs rely heavily on unification, or the ability to produce multiple sounds and tonal registers from a fewer number of ranks than would be the case on a typical church instrument. In church organs, each stop is usually a rank unto itself. There may be one flute for the Great, a separate flute rank for the Swell, and individual ranks may be used at different footages, whereas in a theatre organ, the flute on several manuals, and at several footage ranges, may all be derived from a single seventy-two, eighty-four, or ninety-six note rank of pipes. This "borrowing" of tones is called unification, and it is a development that came on the scene with the development of the American theatre organ.

The theatre organ began to see its demise with the advent of talking pictures in 1929. Some theatres continued to use their pipe organs for sing-alongs and other performances, but the heyday of the theatre organ had come to a rapid and resounding close by the early 1930's.

In the 1950's a new generation of Americans began to rediscover the theatre organ. Electric Organs made by Laurens Hammond, and several other firms, were being sold to homes in the way that pianos had been previously. A new generation of children were learning to play the organ, and interest was directed to resurrect the remaining great theatre organs of the past. Musicians such as George Wright, Jesse Crawford, and Don Baker, who had been directly involved in the theatre organ era, began to perform on resurrected organs that remained in theatres, or which had been moved to private residences and recording studios. America's baby boomers thrilled to the sounds of the organs that their parents had come to take for granted back in the 1920's, and a great movement to restore and feature original theatre organs in performance emerged. It was this interest in organs that brought about the founding of the American Theatre Organ Society. Many organs that would have otherwise been lost to the elements or to the wrecking ball, were brought back to life. Today, several major theatres and performing arts centers are again bring their pipe organs up out of the pit to thrill another generation, and countless hobbyists have set out to preserve theatre organs in theatres, restaurants, churches and even private residences.