Theatre Organ History - Innovations

What made the theatre organ different from the kind of organ found in churches and concert halls? Obviously, it had a very different job to do.

First and foremost, the theatre organ had to accompany the silent film, providing appropriate sound effects as well as background music. It had to permit stylish performance of the popular music of the day. In other words, it had to successfully imitate the dance band. It also had to perform the more traditional role of the organ at that time, namely the accompaniment of group singing and the performance of orchestral transcriptions.

Many of the innovations which furthered the evolution of theatre organ design simply allowed it to do its job better. 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. Some of these important developments are:

Electro-pneumatic action
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.

Unification
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.

Horseshoe console
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.

Traps, toy counter, and effects
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 piano, drums, cymbals, xylophone, marimba, orchestra bells, chimes, castanets, woodblock, and even tuned sleigh bells could be played from the organ keyboards. Sound effects such as train and boat whistles, car horns, sirens, bird whistles, and an imitation of ocean surf could be used to great effect at appropriate times during a silent film.

Increased wind pressure, pipe placement, and volume control
 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
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.

New tonal colors
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.