When the organ began, it wasn't much larger than my laptop. Able to be placed on a desk, it was a single octave or so of keys attached to a single row of pipes which sounded like flutes. Rich people with time for leisure could play them at home for entertainment. And the organ began to be used for religious festivals and circuses. This was in the days of the Roman Empire, however. When Christianity began to flourish, its practitioners wanted nothing to do with the pipe organ, seeing it as a pagan instrument.
Which is a shame, but it tells you something about humanity. Most people didn't have the vision to think that this instrument could be put to new uses; they were hung up on the associations they already had and couldn't see past them. Even today, most people who don't attend traditional services at churches where the organ is played regularly often think of the instrument only in connection with "the Phantom of the Opera" or some Halloween movies they've seen that feature the organ at full blast playing something awesome and scary.
Full blast--the only organ sound that is available on most synthesizers as representing the sound of an organ. Which is in itself interesting. Interesting, and very outdated, just like the notions of many people alive today. It isn't that people don't often share the very same opinions and ideas about the way things work with the top experts in the field, it's that those notions were held by those experts a few hundred years ago, and they've since moved on. Some of us haven't gotten the updates yet.
For nearly a thousand years the organ wasn't considered worthy of being a sacred instrument. But it grew, nonetheless--it had, too. When, around the tenth century, the organ made its move into the church, the architects had created massive edifi of stone; a huge, resonant space. In order to project in there you needed a bit more power than a simple row of flute pipes. And eventually, medieval organ builders began to create groups of pipes that didn't sound like flutes at all. They began to experiment: If you covered the pipes on the ends, you got a different sound, If you shaped the pipes like cones or added reeds which could vibrate when the air flowed through the pipes you got a different sound. Smaller pipes would make higher notes, and smaller groups of pipes would sound higher octaves. Wooden, instead of metal, pipes presented more possibilities. However, with metal you could experiment with different alloys, and you could bend the pipes so you could get longer pipes to fit in shorter spaces. All of these experiments began to take place because, while many people are out not getting the memo, a few restless inventors are always trying to see what would happen if...
But in the middle ages, independence--individuality--wasn't a concept that had caught hold. People didn't think or speak freely on their own, they acted at the behest of their ruler, and they believed what the church told them--or at least they kept quiet about it! So too when music began to be written down it consisted of a single part. Everybody sang the same notes, the same melody. There is no written evidence that there was anyone else singing or playing something different at the same time. No independently moving parts.
Which might explain why, even when several different kinds of pipes, with their several different kinds of sounds, created an organ that was much larger, more powerful, and potentially more various, the first thing they did was to join everything together in one universal full blast, and everything--every note you played on that organ--featured all of the stops going, all of the time. They called it blockwerk.
Today, we can call up any one group of pipes, any flute sounds, reeds, strings, mutations, or mixtures, and have only that single sound. Or we can combine them with others--two, three, four, or everything. The organ can be loud, soft, or in between. Not so in the middle ages. Poets of the times wrote about how the organs sounded like thunder; one tells of how, with the Cathedral doors open, the whole town was filled with sound, which was apparently standard operating procedure.
In an age without jetplanes, factories, rockbands, or anything else that makes a considerable racket, you can imagine how loudly these instruments must have seemed, even if they were no louder than a middle-sized organ playing at full blast would be today. One thing is certain: they were not subtle. And they probably weren't effective playing partners in alternation with the mystery of chant, except by contrast.
None of these instruments survives today. The earliest organ that still plays is from the early 15th century, and most of the pipes on that instrument aren't original anymore.
It would be fascinating to hear an organ from the Middle Ages, but alas, this is one of the mysteries of history. Besides, to hear contemporary accounts, you wouldn't have needed to travel far to hear one. You could simply open your window!
I've found some videos of that "oldest organ"--in Sion, Switzerland. The series is in German, but very entertaining even if you don't speak the language (there are a few Dutch subtitles to help you!)
It is divided into three 8-10 minute segments
part one this is mostly buildup, but you eventually get to see the organ
part two features a trio for two alpenhorns and organ
part three a bit of history of the organ in between numbers including an explanation of how the ancient hydraulis worked (which you remember from my post last week, of course) and a duet for -- well, you should watch it.