The Virtual Pipe Organ

Kenneth Spencer has been a keen amateur musician since aged twelve, playing mainly guitar, piano, organ and keyboards. He has combined his other hobby of electronics & computing to produce radios, an oscilloscope, amplifiers, a synthesiser, and several electronic organs as well as his Hauptwerk instruments.

In addition to his many articles on various subjects, Kenneth has written three books: “All about Hauptwerk”, “All about your Computer”, and the very expensive and large “The Polychronicon – A 35 year Adventure” which records the adventures of a long term Dungeons & Dragons group.


If you visit and read The Organ Manual website regularly, it is quite likely that at some point in your life, you have wished that you could have at home the kind of pipe organ that you play regularly in your local church or chapel. And if you have achieved that goal, congratulations.

When I was about twelve years old, I used to sit in the choir of my then local village Methodist Chapel, and watch the organists. Unbelievably, in the small community, there were three; there was also a larger Anglican church in the village with a bigger instrument and even more organists! And I used to think: wouldn’t it be fantastic to be able to play an instrument like that – and even better – to have one at home to play at any time, summer, winter, night or day.

Sadly, (well, not really sadly), within very few years, my guitar playing took front seat in my musical life, and I was soon playing lead guitar in bands around my home county. But the pipe organ remained in the back of my mind, as the most interesting and challenging of all musical instruments, and having a pipe organ at home would in due course once again become of significant interest for me.

In my late 20s I purchased an upright piano; shortly after that, I bought a small electronic organ. I soon realised the shortcomings of electronic organs for those wanting an authentic sound of pipes. I added pedal stops to that electronic organ and built an analogue synthesiser to sit on top of it – a sort of domestic “Rick Wakeman” setup! But I could not get the genuine sound of pipes I wanted.

The problem: “electronic” organs use oscillators to generate their sound, producing something akin to sine, square or triangular waves (crudely, flute, reed or string), the timbre of which may be altered by various filters. But that technology, although musical in its own right, for many reasons just does not emulate properly the distinctive sounds of so many types of real organ pipe.

So, let us fast forward to the start of the second Millennium. Unbeknown to me, a gentleman in the west of the UK, Mr Martin Dyde, apparently had a similar yearning to be able to play a pipe organ at home, but without the cost and space issues of buying and housing such an instrument – my plight exactly. Martin came up with what was at that time, a novel idea. He was working in the  software & computing sector, and considered that it should be possible to record an organ pipe, and have a PC play that recording back in response to a press of a key of a music keyboard. He also knew that there was a musical instrument control system which by then had been in use for some decades, so-called “MIDI” (musical instrument digital interface) which would allow him to systematise the arrangements for playing recordings of a whole rank of pipes – and indeed selecting combinations of ranks – simulating the playing of the pipes of a real pipe organ, and generating the sound of real pipes. At some point around 2000-2 Martin coined the term “Virtual Pipe Organ” to describe his new instrument. Martin released his software system for the Virtual Pipe Organ in 2003, and named it “Hauptwerk”. He named his company “Crumhorn Labs”, since then, perhaps unfortunately Americanised after its sale some ten years ago.

I encountered Hauptwerk in 2006, when I first discovered the concept of the Virtual Pipe Organ and was considering whether it could be the answer to my interest in the pipe organ at home. Hauptwerk was not the only such software system: one popular virtual pipe organ program was (and still is) “Grand Orgue” – an open source software project. But Hauptwerk seemed to me to be the best of those which I had discovered.

So, how does Hauptwerk work? First, you do need real pipes – a real pipe organ, preferably in a good acoustic, ideally nicely in tune and in good order. However, it must be said that an organ in poor condition, or out-of-tune, can have its recordings improved for use in Hauptwerk. Martin chose a 30-stop 1907 organ by Brindley & Foster in the parish church of St. Anne’s in Moseley, in Diocese of Birmingham. He recorded each pipe very carefully. Although referred to as “sampling”, the recordings are hardly just samples, as every pipe is recorded and is used only for that pipe. Each recording is several seconds long, sometimes even 20 second. So Hauptwerk organs are “recorded” rather than “sampled”.

Classical, concert hall, cathedral & church organs are usually recorded in their natural (‘live’) acoustic – so-called “wet” sample sets, whereas theatre and cinema organs are usually recorded in as much acoustic isolation as possible, often inside the pipe chamber – “dry”.

If the organ is to be recorded “wet”,  more than one recording of each pipe is needed, ranging from a brisk staccato to long legato. This is because a large acoustic responds very differently to short the sharp stab of a staccato note compared to a smooth prolonged legato style. The building sends back multiple separated echoes in response to the former, and a long smooth reverberation after the latter. For proper acoustic realism (which is what we are striving for) the software must monitor the note duration, and play the release “tail” of the recording which best matches the note duration. When playing a well-produced organ sample set, this feature is key to a realistic organ playing and listening experience.

Noise reduction in the recordings is also important: dozens of noisy recordings of pipes played simultaneously in a “big” chord, or likewise, in very quiet registrations, will reveal unacceptable levels of hiss.

The third problem is how to sustain notes which are held for longer than the original recording – “clicks” would be audible each time the recording ends and restarts. “Looping” software analyses the recording so as to identify the best matching zones for volume and phase nearest to the beginning and end of the recording so that playback may continue without audible evidence of a join.

Thus, all these recordings are packaged with photo-realistic images of the organ into a “Sample Set” which can be installed with Hauptwerk, and set up for playing – yes, sounding as though you are in the original building!

It is relatively straight forward to set up a Hauptwerk organ console as most digital organs of the last 20 or so years, are equipped with MIDI IN and MIDI OUT sockets which can be connected to a reasonably powered Windows PC or Apple Mac, and configured to play a Hauptwerk organ. The stop switches, rocker tabs or draw-stops of such an instrument can also be configured to control the virtual instrument.

Many enthusiasts have constructed their own console. Online searches will reveal them and give you inspiration. MIDI keyboards and pedalboards are quite readily available. For draw stops and other controls, you may use one or more touchscreen monitors, although they lack haptic tactile feedback. Novation LaunchPads are also popular, as these provide 64 or 80 configurable illuminated buttons which can be labelled for control of stop names or couplers, and other controls. Audio can be provided by stereo headphones, or stereo or multiple channel speakers.

If you have several virtual organs installed, a programmable stop and control labelling system helps. Although very expensive as part of commercial Hauptwerk consoles, they can be constructed much more cheaply than the commercial cost suggests.

I have built four Hauptwerk consoles over the past 13 years. Two were for my own use: OPUS I, had low-cost MIDI keyboards and a re-claimed, reconditioned pedalboard. Initially controlled by touchscreen, later, it was equipped with two Novation LaunchPads. It started with just a stereo speaker pairs, but ended with a 7-speaker multiple audio channel configuration. It was sold after twelve years of use. OPUS II my very recently completed Hauptwerk organ, has a full control system permitting startup & shutdown; organ, combination set & temperament selection; full 1000 stepper set programming & selection; audio & MIDI recording; and more. It also has 68 fully programmable electronic labels on the stop jambs which can display 120 stop text details and useful details of the currently loaded organ. OPUS I and OPUS II are shown below.

Kenneth A Spencer, ‘The Hauptwerk Virtual Pipe Organ’, Organists’ Review, December 2013,18-23.
James McVinnie, Book review: ‘All about Hauptwerk’, Organists’ Review, December 2016, p73.

For more details, and construction projects, see:


If you would like to write a ‘Monthly Feature’, do please get in touch. It can be about anything to do with the organ. Perhaps your experience on a course you’ve attended, buying a new organ, the day in the life of an organ builder, my favourite organ. I’d love to hear from you!

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