The theatre organ, including the well known Mighty Wurlitzer, came into being in the era of silent film. The large movie palaces of the early cinema often had an orchestra to accompany the film, while smaller venues used a simple piano. But the full orchestra was expensive. The piano, while cost effective with but a single pianist to pay, didn't fill the theatre with a suitable volume of sound.
Theatre owners soon hit upon the idea of installing pipe organs, the musical instrument of choice for the similarly cavernous churches of the time. In the beginning, church organs were installed, but these were suited to the hymns and dirges of the church, not to popular tunes. Collaboration between the Rudolph Wurlitzer Company of New York and English inventor Robert Hope-Jones led to the creation of the Wurlitzer-Hope-Jones Unit Orchestra, commonly called the "Mighty Wurlitzer" theatre organ. Other builders such as California's Robert Morton Company also took part, but it was Hope-Jones who consistently innovated with new design ideas and capabilities.
In addition to the stirring sounds of the church pipes, theatre organs were called upon to imitate jazz, swing and marching bands, and to do innumerable sound effects such bells, horns, whistles and even the crash and roar of the surf. To do all these things, complex systems of wiring and stops were added and a distinctive horseshoe console was developed. The musicians who best mastered these complex consoles were able to support themselves by touring and giving concert recitals.
Thousands of theatre organs were installed across North America and elsewhere, not only in theatres but in auditoriums and sports venues which also saw the advantages of the theatre organ's versatility and its ability to fill a large space with sound.
In 1927 an event happened which signalled the demise of the theatre organ. The Jazz Singer featuring Al Jolson was released - a talking picture! It was soon possible to replace the expensive and space consuming pipe organs with speakers. At the same time, the Great Depression meant many of the largest and most luxurious theatres closed their doors. Many were demolished, organ pipes and all.
A final blow to the theatre organ was the arrival of the pipeless Hammond organ. Soon only the sports auditoriums held onto their theatre organs, rousing the fans with cornball charges and goofy sound effects. Even this traditional sound is now all but lost, with today's sports market focus on the youth market and driving rock and rap played at every break in play.
However, some theatre organs have been preserved in private homes or historical settings. Societies like the American Theatre Organ Society and England's Cinema Organ Society exist to restore and protect the surviving organs. Many of the intact organs can be heard in concert, played by a small cadre of touring organists.
If you have never heard one played, or have only heard them pound out simple tunes at a sports event, you may be surprised by the range and richness of the theatre organ. If you have the opportunity to attend a theatre organ concert, by all means check it out. You may find yourself one of the youngest people in the room, but that won't spoil your enjoyment of the resonant tones of the "Mighty Wurlitzer" or its cousins.
Transitional Man says The original rising/descending Wurlitzer was preserved and is stil in use at the ornate Akron Civic Theater.
Sources include http://www.atos.org/ and a pamphlet from Toronto's Theatre Organ Society.
I attended a concert at Toronto's Casa Loma, home of Wurlitzer Opus 558 which formerly resided at Maple Leaf Gardens and before that at Shea's Hippodrome Theatre. Most enjoyable, I would certainly recommend it.