Go back to Section index
Go to previous part
Go to console diagrams
Go to next part
The console of a theatre organ is the only part which is similar to some electronic organs, although it is probably much larger and more complex than the console of your home organ, even if that is of "theatre style". The photographs accompanying our tour of the theatre organ console are of a Wurlitzer organ of fairly large size (three manuals and fifteen ranks of pipes), the "Style 260" model, like the one once in Brisbane's Regent Theatre. This incorporates most of the features to be found in Australian theatre organs, although smaller instruments will not contain them all.
Even those well used to playing home electronic organs may feel somewhat daunted when facing a theatre organ console close-up for the first time. The eye is first attracted by the sweeping horse-shoe-shaped curve of stopkeys (stopkeys perform the same function as the church-organ's drawstops, but occupy less space). Even the smallest theatre organ will have perhaps sixty or more stopkeys, and a large instrument may have two, three or even four hundred.
It is a colourful array of red, white, amber and black tabs in accordance with a simple colour-code (white for diapasons, violins, flutes, tibias, etc. - the "flues", red for woodwind, brass, etc., - the "reeds", amber for cÚlestes and other undulating stops, and black for couplers), all within easy and instant reach. On Compton organs there are no amber tabs, and on later Christies, cÚlestes are white and couplers are blue. Prior to 1933, Christie used an elaborate system of colour-coding for its stops. This fell out of favour when organists played under coloured spotlights, as many of the tabs became illegible.
As can be seen from the diagrams, the stopkeys are laid out in a logical order, in divisions, controlling, from left to right, the pedal organ , accompaniment (lowest manual), great (centre manual) and solo (top manual) . Within these divisions, the stops are generally in order of volume, loudest on the left, within pitch. Reeds are not usually separated from flues. Above the solo manual is a row of half-length stopkeys. Those on the right are the tabs for the tremulants, or vibratos, and the other stops are for the second-touch and pizzicato effects. Above each stopkey is a circular marker indicating in which chamber the pipes or percussions it controls are located. On Compton organs, pressing hard on a stopkey cancels all other stops in the division in question. On Christie organs, a cancel button for each division is fitted to earlier organs above thata division's stopkeys. On later Christie organs, the divisional name-plate, when pressed, acts as acancel bar.
Second-touch is a feature found almost exclusively on theatre organs. On Style 260 organs it is available on the accompaniment and great manuals and (and also on the pedals). Both of these manuals function normally when the stops in the horse-shoe rows are used. However, the keyboards have an additional set of contacts, so that if the organist presses harder, the keys can be depressed below their normal limit, into what is called "second touch", where additional stops can be sounded.
This effect can be used to emphasise counter-melodies, whereby the right hand plays the melody on the great or solo manual, and the accompaniment is played by the left hand, using the accompaniment manual, with say, string stops. With the Tuba set on second touch, by pressing harder with the fingers playing the counter-melody, these notes may be brought into greater prominence. Another of the many uses of second touch is to play both the melody and the accompaniment with the left hand,picking out the melody by pressing those notes through into second touch, thus leaving the right hand free to provide embellishments on another manual, perhaps on the piccolo or glockenspiel. The drums, cymbals, etc., may also be played on second touch on the pedalboard by pressing the pedals harder at the appropriate moments.
Pizzicato is an effect whereby certain stops sound only for the first fraction of a second when a note is played, thus giving special emphasis to the start of each note or chord, rather like the percussion effect on an electronic organ. This effect is of fairly limited use, but can sound to good effect in "rhythm" playing with "big band" sounds. The only Australian theatre organs equipped with pizzicato were Wurlitzers of Style 260 and larger.
With the exception of some of the very small organs with piano consoles, none of which still exists in Australia, the manuals on theatre organs are invariably of 61-note (five octave) compass, and the pedalboard has a compass of 30 or 32 notes. Below the manuals are white buttons, known as combination pistons, or more commonly, just "pistons" . These operate in the same way as pistons on a church organ, and when pressed, cause the stopkeys for the manual in question physically to move up or down to preset combinations of stops. They are invariably able to be adjusted to suit the organist, either by means of a switchboard, or, on some instruments, by a computer system.
To the left of the pistonson some organs are oval tablets, inscribed "suitable bass". Pressing one of these will cause the pedal stops automatically to change to balance the stops set on the manual in question. Pressing it harder will "lock" the device, so that as stops on that manual are changed, the pedal stops will continue to change automatically to maintain a balance until either the suitable bass tablet for another manual or the "release" piston is pressed.
There are further pistons operated by the feet. These most often control the silent film effects and a few pedal stop combinations. On most makes of organ, these are labelled, but not on Wurlitzers, where it is advisable to check beforehand which piston operates which effect. Failure to do this can result in some surprises for organist and audience! On most organs, some of the toe pistons act as combination pistons for the pedal organ.
Next to the toe pistons in the diagram are four balanced (pivoted) pedals . Three of these control the swell shutters of the organ's pipe chambers (in this example there are twochambers). From left to right, they control the shutters of the main and solo chambers. The third pedal is amaster swell pedal, which can be set to control either or both of the chambers' shutters. This pedal also controls the volume (expression) of the piano by varying the force with which the hammers strike the strings. Up to sixteen degrees of expression may be available in this way.
The far right pedal is the general crescendo pedal, which, as is it tilted forward, gradually adds the stops on the great manual and the pedals (sometimes on the accompaniment as well) up to full organ, but without physically moving the stopkeys. A plug-board, resembling an old-style telephone switchboard, accessed from the back of the console, is used to set which stops are added, and in what order. On organs that have been rebuilt with solid-state control mechanisms, the general crescendo pedal is set by programming the computer. On most Compton organs, the general crescendo pedal cancels the tremulants as well as adding stops. Further right still are metal levers, which when depressed operate drums, thunder, full organ effects, etc.
Below the music desk on some Wurlitzers (but not the one in the illustration) are small levers, which move up and down to indicate the positions of the main, solo and master swell pedals. Wurlitzer organs did not have an indicator for the general crescendo pedal.
As the original purpose of theatre organs was to accompany silent films, they would thus be played in at least semi-darkness. They are therefore often provided with shielded lights shining on the stopkeys. On the console there is often a switch for the blower motor and switches for the console lift, and if the console was mounted on a turntable, for that as well.
All the controls on the console, including the keyboards, are basically electrical switches. The console is linked to the organ chambers by a thick cable containing a wire for every stopkey, every note, and every other control, plus a single heavy-gauge return or "common" wire. In some of the very latest installations, this complex cable has been replaced by just a few wires; this is made possible by a time-multiplexing system. Wurlitzer and early Christie consoles are also linked by a flexible air pipe, which conveys wind from the blower to provide the motive power to move the stopkeys when a piston is pressed. On Compton and later Christie consoles, pistons move the stopkeys by electro-mechanical means, and no air supply is required in the console.
Go back to Section index
Go to next part