A theatre organ (also known as a theater organ, or [especially in the U.K.] a cinema organ) is a distinct type of
Theatre organs are usually identified by the distinctive horseshoe-shaped arrangement of stop tabs (tongue-shaped switches) above and around the instrument's keyboards on their
There were over 7,000 such organs installed in America and elsewhere from 1915 to 1933, but fewer than 40 instruments remain in their original venues. Though there are few original instruments in their original homes, hundreds of theatre pipe organs (typically rescued from defunct theaters or from venues no longer using and maintaining their organs) are installed in public venues throughout the world today, while many more exist in private residences.
Many organ builders supplied instruments to theatres. The Rudolph
Many of the design elements of the theatre organ simply allowed it to do its job better than anything else could. Although not all of these ideas originated with Robert Hope-Jones, he was the first to successfully employ and combine many of these innovations within a single organ aesthetic. As described on the website of the
This uses low-voltage electricity to transmit the action of the organ keys to the pipes. Earlier church instruments used a mechanical linkage of rods and wires to connect the keys to the pipes. With the new system, the console (also known as a key-desk) could be placed at virtually any distance from the organ's pipes and could be somewhat portable, as just an electrical cable and flexible wind line connected the console with other parts of the instrument. This also allowed the console to achieve its ubiquitous place—on an elevator platform in front of the stage, low in the orchestra pit for accompanying the film, and rising majestically to stage height for organ solos.
Previously, each rank of pipes could be played on only one manual (keyboard) at one pitch level. (A rank is one graduated set of similar pipes that produces a distinct sound or tonal color.) In other words, there was one pipe for each key on the keyboard. With the advent of unification, ranks were extended by adding more pipes and made playable at different pitch levels, and on different manuals. Thus, fewer ranks (but with more pipes) could be used in a wide variety of combinations and pitches, and on different manuals simultaneously.
To turn the pipe ranks on and off, the traditional organ console used drawknobs placed on panels on both sides of the manuals. Using electricity, Robert Hope-Jones substituted tongue-shaped tabs arranged on a curved panel around and above the manuals. These stop tabs could be quickly and easily flipped up or down to select or deactivate any ranks of pipes.
Real musical instruments, not previously associated with the pipe organ, were installed in the pipe chambers to be pneumatically operated at will by the organist. Such instruments as
Higher wind pressures increased the speaking volume of theatre organ pipes, and they were placed in chambers, usually high in the auditorium. The fronts of these chambers were covered with a set of swell shades which opened and closed like venetian blinds. When closed, the sound of the organ was reduced to a whisper. With a foot pedal, the organist could gradually open the shutters to produce louder and louder sounds from the same pipes. Although this type of swell chamber was not new, theatre organ developments permitted a much broader dynamic range than ever before.
Tremulants are devices that create a vibrato effect by mechanically shaking the wind source or by other means. Although the organ tremulant had existed for centuries, it was dramatically refined and changed in the theatre organ, and was used in entirely new ways. Traditional organs used tremulants only occasionally on solo stops. The theatre organ tremulants—smoother and broader than ever before—now became the standard, defining characteristic of theatre organ sound.
Robert Hope-Jones and others designed many new kinds of pipes in an effort to create colorful sounds for the theatre organ. Many of these new stops attempted to imitate the sounds of real orchestral instruments, while others simply contributed unique new colors to the tonal palette. Important new stops invented or refined by Hope-Jones included the Tibia Clausa, Tibia Plena, and the Diaphone.
These are but some of the basic differences between traditional concert organs and theatre organs, highlighting the elements which make the theatre pipe organ a unique instrument.
After some major disagreements with the Wurlitzer management, Robert Hope-Jones took his own life in 1914—but not before profoundly influencing the development of the theatre organ. The Wurlitzer company continued to flourish, becoming the largest manufacturer of theatre pipe organs in the world. Indeed, while there were many other builders of these instruments, the name "Wurlitzer" became generically synonymous with the theatre organ.