Beast: Hacking the Virtual Organ

Introduction: What can we do with this virtual organ?

Organs are a kind of additive synthesizer in the way you look at it from beast. In reality they are huge and enormous complex instruments that can not be simulated by computers or better: not with beast yet. Or better: I cant do it and I tried hard to do my best.

But what I can is to present a virtual organ that is quite a nice instrument for itself and sounds complex and good enough to beat the shit out of most wannabe organlike synth or even to sound (subjective) better than some $50.000 chamber organs and is a fair match to most of the synthetic organs that are on the market. We have a nice complexibility that can match some of the most famous church organs in europe and between this and the gigantic monstrum in philadelphia or the even bigger atlantic city boardwalk hall organ are maybe only one to three CPU generations. That last thing has around 30k pipes and 7 manuals and we really cant compute this complexibility. Not even halveway. But that was not the goal: the goal was to build a fair useful virtual organ and that's where we are now. Anybody that isn't satisfied with this can buy any church organ he likes for 250.000,- Euro up to some millions. They are indeed nice instruments I adore very much.

The way to make an instrument

There are two ways to build such an instrument. The first way is to record every pipe of an organ you like and to play every combination on any key that is pressed. This is the way the software Hauptwerk works or the free project myorgan. Going this way you'll get very nice sounding copies of existing instruments but you will only get a more or less bad copy. Thats always the problem of a sampled instrument: it's not origin.

The second way is to calculate and simulate the sound of each pipe. The only project I know that tries to simulate an organ like we do with this beast-instrument is the free project Aeolus. This well done organ is ready to use but has some disadvantages. First, you can't really expand this organ without heavy hacking, second on my system I have problems with the qualitiy of the audio output. Maybe its my system, maybe my hardware, maybe a problem of that project (what I think most, cause I had the same problems on every hardware I tried).

So I did it with beast. If anyone likes the sound of one specific pipe of one specific organ he's free to include this as a waveform-pipe into beasts virtual organ, too. But that was not what I done.

Some principles of organs

A real organ consists of some simple parts that you have to know first before you can understand how an organ works. First there are the manuals. The manuals are the keyboards of an organ an with each manual you may play different configurable sets of pipes. Most church organs have two manuals, one main manual the "Hauptwerk" and a right behind that a second the "Hinterwerk". Additional to these two manuals there are the pedals ("Pedal"). Each manual has from 3 to 5 octaves, the pedal not more than 2 octaves and are played just like the white/black keyboards you'll know from every synthesizer or piano keyboard. There may be organ with up to 7 manuals and other with only one and even no pedals. I don't want to talk about this, because we will go a complete other direction with our virtual organ anyway.

On an organ you have no velocity dependence when striking a key, its not piano-forte as on the piano that you can control the volume of your tone by hard or soft hitting the key. The tone will normally come with one volume. I implemented a velocity dependence for the organ in beast because you simply can turn off this feature on every keyboard but I think some people will have problems to implement it if its not included in design. You will need velocity dependence on some rock- or jazz-organs so I put it in, just in case. With using the church organ pipes of this instrument I strongly recommend to turn this feature off on your keyboard for normal use or filter the signal through QMidiroute or other midi-filtering devices.

Every manual has a selection of pipes you can play with it. When pulling a stop you turn on a certain pipe or push to turn the pipe off. These stops are named "Zug" in german, I have to refer to some german names with using organs because many pieces for organ are from german composers and you possibly will not find an english version of the piece. This should help you.

The selection of pipes you play with a manual is called the registration. All pipes together (whether they are played or not) is called the disposition. The disposition is therefore the design of the pipes you may play, the registration your personal choice when pulling stops, you may call this preset if you like a non-organ but more synthesizer-style name for it.

Effects and digital churches

Additionally to the disposition of an organ and the choice of pipes we have some effects we can use. Some organs have a build in tremolo for every manual. And on other organs some pipes can be hidden in closable chambers, the sweller or "Schweller". This dampens and silences the pipes. On older organs the closing can not be changed during the play on some modern variants the chambers can be changed. The tremolo can be turned on or off for a manual by stops.

There may be some more effects that some organs may or may not have but they are very specific and I ignored them completely. Because you can easily build any effect you want anyway and I will show this later on this document. The only global effect is the sound of the room of your organ. This effect can be added to the whole organ because the church should be considered as a whole resonant dramatic effect of every organ itself. Its build with some reverb effects but I will come to this later. If you dont want this and prefer a dry organ because you have a church for yourself to play beast in you should turn this effect off. If you turn it off and play it in your living room you will be disappointed by the dry sound.

The parts of this virtual organ

First there is a disposition of the virtual organ. There are dispositions for one, four, five or eight and even nine pipes ready for use. For using this you should take that with one pipe as a solo pipe and that with four pipes for playing more. In most cases you should not need any other dispositions because when playing more than four pipes together you may mangle the sound. Sometimes less is more and a clear sound is better than a howling storm of nine pipes where you can not recognize the melody or the chords anymore. And those two dispositions have also the advantage to use very few CPU power.

To be precise with this two dispositions you will join together a disposition and a registration. Because with changing the registration, using other pipes, you will have to change the whole disposition of your organ. The names of these two dispositions is HNO Disposition - solo voice and four registers.

The larger dispositions like the chamber organ (5 pipes) or the church organ with 3 ready to use manuals with up to 9 pipes each will eat much CPU power while playing. The advantage is, that you can turn on and off pipes by mixing in the sound through the mixers or turn on and off pipes by putting the pipes in the slots or taking them out. Putting in and out has the advantage of less CPU usage but you have to remember which pipe was in which slot. I will tell you more about slots later.

My recommondation is the use of the one and four pipe disposition while the advantages are on hand: easy to use, low CPU usage, simple setup of the synthesizer.

The pipe slots

Pipes are no instruments for themself. They only can be played within a disposition. Pipes are virtual and can be taken in or out of any disposition to change the sound of your organ by a very complex and flexible way without consuming unnesessary CPU power.

Each disposition has a certain number of pipe slots. These slots are implemented as virtual subsynths where you put in every HNO pipe. With later versions of beast you may calculate frequency changes like octave up or down or quint, quart or terz transponing with the transponing module, now you have to do this with calculations like multiply with 2 or a halve or any other step you need.

To build a new disposition you simply load the right disposition template without any pipe clipped in because that pipes would unnecessary double in your virtualorgan-bse. Then you clip into the slot the needed pipes. You can chose from a broad spectrum yet, but I'll work on that to make it broader and the pipes better and better I hope. If you don't find the pipe you need, feel free to take one of the ready ones and change it up to the sound you need. The community would be happy if you publish that pipe afterwards but that is completely up to you.

With this first release we have a spectrum of church like pipes but I hope we get some more in future, some seldom ones too and I hope I'll find time to work on funny ones like a howling wolf pipe, vox humana, whistling or more jazzlike ones or Hammond "pipes". The sound of each pipe is completely up to you and the virtual organ can really play everything, even recorded wavs as pipes, so you should be ready to create every sound you want. I wont go into the creation of sampled instruments in this article further but that's a mighty tool that shouldn't be underestimated.

The creation of useful and good sounding pipes was the dream of every organbuilder since the first organ was invented. So feel free to be creative with this. The virtual organ has a unique sound and is a unique instrument for itself. Its not a copy of anything. The theatre organs have been gone this way before. But I think with a mighty softsynth like beast in the back you should kick in some interesting new features to this kind of instrument, don't you think?

Using dispositions

The best way to show the use of a disposition is in an example I think. While we have no way yet to switch from a certain "program", means preset, to an other by MIDI control commands with beast we have to create every registration we need before we start making our song. The only way to do this life would be to use the ready made MIDI active church organ disposition or the less CPU consuming MIDI active chamber organ disposition you'll find between the other dispositions in the virtualorgan. With these two dispositions you can create the range of pipes you want to switch on an of with MIDI "stops" on your keyboard for example (or special midified stop-manuals I dont have for myself).

But I dont think this is very practical for most people who want to use this instrument but those real organists who play that thing life. But beware, you'll need some CPU power for this when you reach a certain complexibility and where I would assume at this stage of the project to play only one manual with each computer but to the moment we'll have the multicore beast, which is planned or more CPU power per core we have now or you build simpler models for the pipes than I did like playing samples for example. Imagine that the virtual organ implements every pipe not by playing simple samples but through some very complex synthesizer designs. But anyway for most computers out there the chamber organ should work well and give you a very nice sound. Thats the reason I put it in where it is. Anyway a typical church organ with two manuals, each 8 pipes and a pedal with 4 pipes works very well on my Core Duo 6600 CPU (even with only using one of its virtal four cores for beast), but begins to suck on smaller computers.

But now I better come back from life-playing that organ to using it as an customable MIDI instrument. If you listen to organs and organists that play on certain ones you will find that they have some limited combinations they use most often because the sound of combination of pipes fit well for a special piece of music or the change of preset (registration) has a certain effect like being broad, bright, spheric or any other timbre you like. To get concrete I find out that the combination of some octaves of principal together sound well and at the top of them I would like to have a certain mixture as the head of the sound. You should find out that the intelligent choice of pipes gets you a very much better sound like simply to "pull all stops" like an idiot that doesn't know anything about his organ and does it after "much helps much" - but indeed its an art and who am I that I give advice to anyone whats right or wrong? That leads to nowhere I think but maybe my own experience will help you to learn to use this organ for yourself.

So I take the four pipes disposition and build my certain sound. I put in the first three octaves of the principal and some head pipes and with this I have a very broad sound at first. Never forget: you have more than one manual and quickly come to play 20 to 40 pipes or more at once on your whole organ even with only using the four pipes disposition for every manual or better for every MIDI-track in your piece of music because on every single manual you will sometimes press three to five keys at once...

You should test the sound with a MIDI keyboard while playing around with your registration until you are satisfied with the sound and effect of it. Then you put it as an instrument for a certain track. For every registration you build an own track with the same method. That will get you a very structured piece of music where every single registration will be seen as an own instrument. Maybe you are used to switch from one instrument to an other like switching instruments life during play but that will get you a more or less spaghetticode piece of music if you view it with the eyes of a mantainer.

Making an example

As an example we'll take a very simple piece of church music for this, like "StAnne?.mid". The fist time you put it in you worked out a certain registration with four beast disposition instruments. You create a solo voice disposition for the melody add a four pipe accompany disposition, an other solo voice for the pedals and maybe you find a fourth track in your MIDI piece of music like in this particular that you dont know how the organists manages to play - anyway. Maybe it was a third manual on his organ he uses or something like that. You have no problem to play this with beast anyway.

After the first strophe you may like to change the registration of one or two manuals. So you put in an other choice of pipes for this. With this virtaul organ you are not limited to only using certain pipes together like on a real organ, you may combine any pipes you have. Make a choir of trombones if you like but you'll find out that this sounds quite messy after doing it, cause the sound of these pipes are far too complex to played together well as a choir (you won't find that in reality). The combinations you may chose and may not chose on organs are well organized so I would assume you get the best experience with limited sets of pipes per manual as with certain historic and famous organs out there. Maybe the page Encyclopedia of Organ Stops helps you with this when experimenting.

You will find some remarks in each HNO pipe like "often used as solo voice", "played together well with a certain pipe" and that. Use that if you like, learn and know the pipes you have. There is no easy way to do this without heavy experimenting. So sorry.

Hacking your organ

So when repeating the song with new registrations you copy the part to a new track and put in there the next disposition instrument to play it. So your piece of music can change its character while you jump from strophe to strophe, like you are used in church music. After a while you will learn to hear that your beast virtal organ can sound much more interesting as an instrument than the organ in your church round the corner when played by the organist. Not that these organs are bad instruments or these organists are bad musicians but most church organs are used only for accompany the singing and are a bit uninspiring after a time you listen.

You find out better if you listen to organ concerts. You dont need an huge and mighty organ to hear a good concerts, you'll more need a good organist for that - that one will play the hell out of any organ you'll let him play. Try to analyse what you hear and let inspire you for your own dispositions. You see that playing the beast organ will teach you some things. Maybe the only thing you'll learn is to love some of the hackers that used to be componist of organ pieces in former times. Reverse engineer that.

Dispositions and their use

• Disposition - chamber organ, you name it this one is ready to use and has five stops included. Its build like the Ott chamber organ but sounds different.
• Disposition - church organ, is where you'll find a Hauptwerk, Hinterwerk and Pedal disposition that orientates itself by the famous Silbermann Organ in Reinhardtsgrimma, Sachsen, Germany but puts some pipes in it to be more flexible. As the first one this one sounds different but does copy the idea, I hope.
• Disposition - four pipes, should have four empty slots and versions with a high sound and one with a lower sound are ready to use.
• Disposition - solo pipe, there are some solo pipes ready to use like the nasat, the trombone, the viola or the trumpet for example.

Additional to this we have some organs as instrument ready to use that are not organized with virtual pipes and are therefore a more ad hoc solution. If you like you may use them too but I don't talk about them here because they are too static models and were build in an early stage of this instrument project.

Effects and their use

You have some effects that you should clip behind a disposition, you can do this when working on a song in the beast sampler. Even if you play this tracks through midi the effects take place.

• no effect, this effect is empty and can be taken as a template to build new effects.
• Simple lowpass filter, this effect softens high pitches of certain pipes and are quite easy to use
• Sweller, you can dampen and silent the sound of the pipes with this effects through using the main volume of your keyboard or with the specific MIDI command. It defaults on channel 0.
• Sweller and Tremulant, adds in a tremolo that can be controlled by the modulation wheel and by the tremolo depth command (CC92)
• Sweller, Tremulant and Chorus, yeah the name says it but this effect is only to show how you can expand the effects if you need them. I never used this disposition in practice yet.

Additional to these after pipe-sort effects you have the global ones, that I call room-effects. You put them into work when building your song. On the properties page of the song you have an postprocessor, just like the postprocessor after each voice. There you can insert

• no effect, again or just leave it blank
• roomeffect cathedral, makes a sound like you are playing the organ in a large room like in a cathedral, my personal favorite
• roomeffect small chapel, is the same effect but less dramatic and intense

The roomeffects can be build in like the EAX effects that you can use on certain modern sound cards and that are implemented by hardware DSP. But to do the same with software makes you much more independant and the effect is always the same and does not differ on a specific hardware. You should use this and no hardware postprocessors. And by the way - you really have no problem to alter this the way you like it. Maybe you want to play the organ in a wide stadium or so then you just have to correct the parameters and thats all.

Tune in

You have to tune every instrument in a special way. Normally keyboard like western instruments are tuned in 12 tone equal tuning. That means the 12 steps between all keys are equal. So this is beasts default. But there's a problem with this: most organs are not tuned equal, they have a midtone tuning. I don't go into the details, I assume you better read about tuning in wikipedia, but you can switch this tuning on the properties page of the song too - and you better not forget this.

Because the midtone tunings or the "wohltemperiert" tuned instruments prefer some keys and take disadvantages on other as the disadvantage of this. It means that in the modern tuning system you have drissling rain everywhere, no real sun, no real rain - its like Douglas Adams names it: "No sun in the desert, just drissling rain everywhere". You have no really bad tempered chords or keys you have no real good tempered ones. And its completely the same where you play a melody - based on C-major or on Cis-major or B-major, it always sounds the same. But with the alternate tunings you can discover the brightness of former tuning systems that made a choice. The most often used tunings are Silbermann-Sorge and the famous Werckmeister-III of cause, that some people call "The Bach tuning".

My advice would be to use this if you can. And when you chose a pythagorrean tuning for example you'll have the sound of a mideval sort of organ that will be brilliant on quintes and awful on a terz. Play around with this but on the current version of beast (0.7.1) the tunings will only work with the internal sequencer, not with MIDI but this is in work progress and will be done later.

The pipes

Learn your pipes. I said: learn your pipes. I cant tell you what to do and not if you dont know them and if you know them, there is nothing more I can tell you about them. You should study a bit on the Organ Stop Encyclopedia I mentioned earlier on this page. So I really make it short.

The typical length of a pipe is 8' (eigth feet) and that one sounds on a typical church manual that you have a A+1 (around 440 Hz, depends on tuning) in the middle of your keyboard. Pipes with greater length like 16' are one octave deeper and usually you only find them on the pedals. Sometimes you may pull them in the main manual to support the principal. On smaller organs you have the "Gedackt" pipes, that are pipes with a closed end that are not open at the end as usual. Those pipes will sound one octave deeper than you should expect on their length. You find one ready for use in the chamber organ disposition but you'll find that they are with less harmonics than the real ones.

• "vox ineffabilis" - or vox inaudita or nihil is an empty pipe. You can use this as a template or to disable a pipe if you don't like to simply delete the text in the slot. Its one of my sick little jokes that I build this pipe, sorry for that. This one makes no sound and costs no CPU power.
• Principal - the work horse of almost every organ is this pipe. They are medium complex and sound awful more complex than a nearly sine wave from the Flute but are far away from complicated Trompones or other brass-like, full and saw-wave sounding pipes.
• Trombone and Trumpet - two more complex pipes with brass-like sound, the first one used most often on the pedals, the second used as a solo instrument.
• Viola da Gamba - one of the most common string-sounding pipes.
• Flute - a typical nearly sine-like pipe with a clear spheric sound.
• Nasat - the hollow sound of a oboe-like pipe.
• Mixtures and Cymbals - high pitched pipes that give a good and bright head-sound for a registration and the inharmonics in the cymbals give a metallic cymbal like sound like the sound of that early piano of that time (that was not velocity dependant indeed like a real piano).

There are many more pipes to choose from in the virtual organ and I'm working on some more of that together they are around 25 or so. Should be enough to build a good disposition anyway.

To noise or nonoise, thats the question

I've put wind noise into some of the pipes into most I did not. I only put them in when I thought that the wind noise softens the pipe and should be considered a part of the idea behind that pipe. I tried to follow the idea of a pipe, not to simply copy the sound. But feel free to change this if you like: the sound of the beast organ is clear and nearly noiseless, completely different in its sound than any other digital organ I had recordings from. Because most of the other ones have heavy noise in them. Maybe noise is always a idea behind every organ but I doubt that. I'm not shure but I came to the point to skip this on most pipes I build, knowing that the pipes will sound different from sample-played ones. But on the other hand its always easy to put noise into something if you want but hard to get it out again after that.

With the mostly noiseless organ we have a new instrument with a really origin and remarkable sound. When I put noise in it, I think, we would only have an instrument that wants just to sound like something it is not. Its not mechanic, so why should we sound like mechanic? The idea behind an organ is a good sounding instrument with pipes that fit together well.

I hope you enjoy this and find that we're on the right way with this. Beast is very much more than just an organ simulator. Its a soundengine, its a softsynthesizer and we can do an organ, but why should we stop here? Why should you stop here? Think about the dreams of the musicans and instrument builders that lived before us, try to catch their dreams and translate them to modern times.

And then: go boldly to places where no man went before.

Happy playing!

Designer: Hanno Behrens