Over the last few weeks, our hardworking organ builders in Massachusetts have made exciting progress on our organ! Jonathan continues to voice our pipes. Having finished the Swell 8’ Stopped Diapason, he has since started in on the Swell 8’ Viola. The Viola rank is, unsurprisingly, a rank of “string” pipes. No, that’s not an oxymoron! String pipes in the organ imitate the bright, harmonic-rich sounds of stringed instruments. Jonathan will imitate this brightness by getting the pipe to have strong upper harmonics: first, he causes the pipe to “over-blow” by forcing too much air through it, causing the pipe to speak an octave higher than it normally would. The sound is now enriched with the upper harmonics present at the higher octave.
Next, Jonathan will stick a “roller” in the mouth of the pipe to get the pipe to speak back down in its normal octave. This roller must be very precisely placed in order to bring the sound back down the octave. Finding that position is an experiment Jonathan must carry out on each individual pipe. Once the position is found, he must carefully secure it, so it doesn’t move. The result of all this manipulation is a sound that is rich in upper harmonics, thereby imitating the brightness of stringed instruments. Because of all this careful manipulation, the String pipes are the most difficult pipes that Jonathan will voice.
Next Tuesday, Jonathan will travel to Connecticut to visit reed voicer Chris Broome. You may recall that Jonathan visited Chris’s shop last month to hear samples of the 8’ Trumpet and 8’ Oboe, where he listened not just for the relationship of volumes, but for the characters of the two ranks. Jonathan gave the green light for Chris to voice the remaining Trumpet pipes, but wanted a darker sound from the Oboe. In his upcoming visit, Jonathan will be able to hear the full rank of Trumpet pipes as well as the new samples for the Oboe. Chris has reported to Jonathan that he is extremely pleased with the beautiful tones and the stability (meaning it will stay in tune well) of the Trumpet. (Reed pipes are notorious for going quickly out of tune. You may remember that I could only use the reeds in our old organ for a few weeks after it was tuned, and then avoided them the remainder of the year).
The Swell Slider Chest has been completed in the last few weeks, and it’s in place and “winded,” meaning pressurized wind has been fed into the chest with good results. We can think of the Slider Chest (last month I called it the “windchest” ― both terms are accurate, as “slider chest” is a specific type of windchest) as a matrix, with the notes of the keyboard running in the x direction, and the ranks of pipes running in the y direction. On the x axis, there is a magnet and pallet for every note on the keyboard; when you press a key, the magnet pulls the pallet opens. On the y axis, there is a slider that either shuts off or admits wind into the entire rank of pipes. So in order for a specific pipe to speak, the stop has to be pulled on and the note must be pressed on the keyboard.
Now that this slider chest is completed, it will undergo rigorous testing to make sure that every component of the action works the way it’s supposed to. They will hook a keyboard up to the chest and play every single note, testing that each magnet opens its pallet properly and that there are no air leaks. With the completion of the slider chest, the set-up of the Swell division is now finished!
Over the next few weeks, our organ builders will begin work on the chest for the Pedal 16’ Bourdon, which will host the largest pipes of the organ. Our Facade pipes (the pipes that are visible in the case) and the pipes of the 16’ Fagotto will arrive at Jonathan’s shop from Shires Organ Pipes, the company tasked with building our pipes. The Oboe will most likely be full voiced. Remember that you can follow Ortloff Organ Company on Facebook, where they post new pictures and updates, along with with extremely helpful descriptions of what you’re looking at, every Friday.