VIRTUAL THEATER ORGAN REGISTRATION BASICS
ENSEMBLES
Ensembles are basically groups of musical instruments playing together. In a Theater Organ, an ensemble is a relatively large group of varied stops usually at multiple pitches playing together often in chorded passages. These are the thrilling 'console raiser' registrations you hear which approach full organ playing some show stopping introduction, or at the final climatic chorus of an arrangement. An ensemble could also be a massed chorus of stops not necessarily room filling but very full sounding for other special effects. There is usually a distinct 'build-up' in these ensembles, meaning the order in which the various component stops are added in when creating the ensemble.
In Walter Strony's book, 'Secrets of Theater Organ Registration', he gives suggestions for some very beautiful as well as thrilling sounding ensembles which he puts in order from moderate in volume on up to Forte, with 'all guns blazing'. If you look at the list of stops Mr. Strony suggests and 'do the math', you could well find yourself with 20 vioces playing for each key pressed. Play a 4 note chord, even cleanly with no gracing (accidental or otherwise) and you have yourself a fistful of voices/pipes/whatever. This is a PERFECTLY ACCEPTABLE way to do things on a pipe organ with 'infinite polyphony', or digital electronics approaching (and surpassing!) the six-figure price range with a staggering voice count. The Virtual Theater Organ must attempt to keep up with that with comparitively limited resources. The basic way in which this is done is by using the stops that are the 'essence' of the ensemble and using some massing tricks such as discrete use of chorusing and detunung in order to create the mass of tone other instruments create with shear numbers of voices.
An ensemble registration cannot be just the 'bare bones' registrations we talked about with the Tibia/String relationships. Even with the Virtual Theater Organ there is some 'fleshing out' or filling out in large ensemble registrations, but this should be done with care. A very full sounding Mezzo Forte Tibia/String/Vox registration can be:
16' Tibia Clausa
16' Viole d' Orchestre (chorused)
16' Solo Vox Humana
  8' Tibia Clausa
  8' Viole d' Orchestre (chorused)
  8' Solo Vox Humana
  4' Tibia Clausa
  4' Viole d' Orchestre (VERY OPTIONAL)
The 4' VDO will add a singing quality to the top end of this ensemble that may be desired at times, and at times not. Listen to it both ways and decide. Notice that the 4' Vox was not added here. This doesn't add much to the overall ensemble sound and takes one more voice per note of polyphony. The registration is already up to 8 voices per note, and is ONLY practical if two 32 voice synths (or one 64 voice 'super size') are assigned to it. If you are using two synths, it only makes sense to divide the voices evenly.
For Mezzo Forte registrations like the above, some authors suggest that you add in Clarinets, Brass Saxophone, Open Diapason, Horn Diapason, Concert Flute, and probably other stuff, too. You must ask the question: "What do these extra stops add to the OVERALL TONALITY of this registration?" If a voice is a 'major player' then include it. With limited polyphony, we can't often afford the luxury of filler stops. There is nothing wrong with these recommendations on an instrument with INFINITE POLYPHONY, however, in the Virtual world, we must be more economical in our stop selection. Incidentally, it may be a good thing that registrations can be changed with combinations only; this keeps the Virtual organist from going hog wild at the stoprail.
If you like the extra wail of the Brass Sax in a registration like this, you may consider substituting the Sax for the Vox Humana. Substitute the Sax first at the lowest pitch (16') and see if this creates the desired effect. Substitute the 8' Brass Sax for the 8' Vox if your taste dictates. I find the 16' substitution is enough. If BOTH voices are present, Sax at 16' and Vox at 8', both of the tonal COLORS are represented. Remember: Substitute the LOWEST pitch FIRST. In a registration this large, you probably will not notice both Sax and Vox not present at both pitches. 16' Sax and 8' Vox may be plenty. Same goes for other woodwinds and color reeds. Register only the most dominant voices.
If a still more massed sounding Mezzo Forte registration (I use that term to define all Tibia/String/Vox/Sax registrations without the addition of chorus reeds) is desired, additional 'ranks' of strings can be called in. If you simply add an additional String at 16' and 8' with similar timbre to the Viole d' Orchestre or Salicional already being played, you will NOT get your money's worth out of it. It is presumed that the String you already have on is chorused. This is adding Celestes and adding nicely to the massing. To make the additional String ranks make their presence known, DETUNE them in the combination. Korg has parameter settings in the programming of combinations whereby a 'program' being brought in can have its PITCH (ie 16' 8' 4' or mutation) altered as well as its tuning. A detuning setting of about 14 either sharp or flat usually makes for a massive effect without sounding out of tune. For Strings, this should probably be sharp rather than flat. The Mezzo Forte Registration below is the fullest non-chorus reed ensemble combination (Piston #7) that I use on my Great Manual. you will hear it throughout the recordings.
16' Tibia Clausa
16' Salicional (chorused)
16' Gamba (chorused AND detuned)
16' Solo Vox Humana
  8' Tibia Clausa
  8' Salicional (chorused)
  8' Gamba (chorused AND detuned)
  8' Solo Vox Humana
  4' Tibia Clausa
Of course the voices on this large ensemble registration are equally divided between the two Korg 01 Synthesizers allocated to the Great.
Reeds (except Vox and Brass Sax) at two pitches such as 16' and 8' may not add that much more to the registration than just one at the lower pitch. Of course try everything out before you hit that 'write' button in your patch edit software.
Addition of chorus reeds should be done sparingly and again, only the ones that 'count'. The above 8(or 7)-stop ensemble registration is an excellent starting point for chorus reed ensembles. You will OFTEN find that one reed or at most two are sufficient. As a basic starter, try:
16' Tuba Mirabilis
16' Tibia Clausa
16' Viole d' Orchestre (chorused)
16' Solo Vox Humana
  8' Tibia Clausa
  8' Viole d' Orchestre (chorused)
  8' Solo Vox Humana
  4' Tibia Clausa
  4' Viole d' Orchestre (OPTIONAL)
To go very full and bright, a 16' Trumpet can be added. Here the Tuba reinforces the Trumpet and makes the overall
registration very full:
16' Brass Trumpet
16' Tuba Mirabilis
16' Tibia Clausa
16' Viole d' Orchestre (chorused)
16' Solo Vox Humana
  8' Tibia Clausa
  8' Viole d' Orchestre (chorused)
  8' Solo Vox Humana
  4' Tibia Clausa
  4' Viole d' Orchestre (OPTIONAL)
That's 10 voices. 12 if you have added additional detuned Strings as I have. At about this buildup I'd call it quits with two 32 note synths; 5 (6) stops on each synth. If you want to top this with a Posthorn, I'd take either the Tuba or the Trumpet out, or maybe with a voice that loud in the ensemble, one of the String voices could come out. Then you might squeeze out one more voice and go for broke and have the 'Big Three', Posthorn, Trumpet, Tuba in the brass department. A 'Filler' Diapason won't do you any more good than a louder Tibia would, and all the other fillers like Concert Flutes, Horn Diapasons, Oboe Horns and the like will get lost in the shuffle. Wonderful ranks on quieter registrations where there tonality comes through, but, in modern music production terms, they don't cut through the mix.
Going back to the basic Tibia/String/Vox combination, any other color or woodwind reed can be substituted for the brass stops to create other interesting combinations. Experimentation here is the key.
For another type of ensemble registration, take the basic Tibia/String/Vox registration above and 'knock the bottom out
of it" by removing the 16' Tibia:
16' Viole d' Orchestre (chorused)
16' Solo Vox Humana
  8' Tibia Clausa
  8' Viole d' Orchestre (chorused)
  8' Solo Vox Humana
  4' Tibia Clausa
Play single notes in the middle of the keyboard, and chorded passages in this ranges, and preferably slightly higher. This
is a nice 'old school' ballad sound. There are a whole mess of variations you can try with this. One is to eliminate the
Vox Humanas:
16' Viole d' Orchestre (chorused)
  8' Tibia Clausa
  8' Viole d' Orchestre (chorused)
  4' Tibia Clausa
If you miss the Vox, but don't want it real strong, Just put in the 16':
16' Viole d' Orchestre (chorused)
16' Solo Vox Humana
  8' Tibia Clausa
  8' Viole d' Orchestre (chorused)
  4' Tibia Clausa
If you want a little more wail to the sound, substitute the 16' Sax for the Vox:
16' Viole d' Orchestre (chorused)
16' Brass Sax
  8' Tibia Clausa
  8' Viole d' Orchestre (chorused)
  8' Solo Vox Humana (with or without-try both)
  4' Tibia Clausa
Here's one you didn't expect: A registration of the same basic character, but substituting Diapasons for the Strings:
16' Diaphonic Diapason
  8' Tibia Clausa
  8' Diaphonic Diapason
  4' Tibia Clausa
Because of their frequent use as 'filler' stops, you may think that for the most part the Diapason is a waste of polyphony in the Virtual Theater Organ. This is not true in registrations where its character contributes to the tone. The Diapason is a very useful voice tonally when it is blended with the Tibia. Here are Three other Diapason/Tibia Registrations where the Diapason plays an important part:
16' Diaphonic Diapason
16' Tibia Clausa
  8' Diaphonic Diapason
  8' Tibia Clausa
  4' Octave
  4' Tibia Clausa
In the above registration, the Diapason admittedly acts as a 'filler' for the classic three pitch Tibia chorus, but the tonality is very distinct. The comparatively milder Diapason tremulant contrasts the heavily tremulanted Tibia. With the usual chamber placement of the Diapason in the Main chamber/Tibia in the Solo chamber, the Diapason adds a stereo effect to an otherwise 'monaural' Tibia chorus registration.
  8' Diaphonic Diapason
  8' Tibia Clausa
The registration above is just a really great registration for chorded passages. The two roundest, fullest ranks in the organ working together. Buddy Cole used to have a couple of Diapasons in his studio organ and used them together in this way. Usually a small to moderate Theater Organ has just one Diapason, so the Tibia can be used instead of a second Diapason. The contrast in tremulants in Tibia and Diapason contributes to a 'massing' effect. Besides the chorded passages, this registration is not bad for single note melody or counter melody in the tenor and upper tenor ranges, either.
  8' Diaphonic Diapason
  4' Tibia Clausa
This above two stop registration sounds a lot cooler than it looks on paper. Any time you add a Tibia one octave higher to a voice with more harmonic content, you get something slightly suggestive of an Oboe-like tone. It can be anything: String (especially) Vox, Trumpet, Tuba, Posthorn, Oboe, Clarinet (VERY interesting). The Diapason is the 'dullest' harmonically of all that could be added (except for the Concert Flute) but the combination is interesting for other reasons tonally. If you have never tried this registration, check it out, it it surprisingly useful.
For more information on
Virtual Theater Organ Registration Basics-Families of Theater Organ Tone
Virtual Theater Organ Registration Basics-The Tibia/String Relationships
Virtual Theater Organ Registration Basics-The Polphony Problem