Organ Tuning: Part 2
by John Coenraads
Now that you have adjusted the reference pitch of your tuner to the overall pitch level of the organ (see Part 1) you are ready to go inside the organ and start tuning. Simply getting inside the chambers can involve unsteady ladders, vertiginous vertical steps, narrow walkways and unstable trap doors. Proceed only if you are physically able and feel safe doing so. Even experienced technicians do get seriously hurt: witness The Diapason columnist John Bishop's fall from a walk board last year. The instrument is also at risk: one misstep can crush thousands of dollars worth of pipes or smash a row of trackers. You are strongly advised to discuss liability issues with the church and seek permission from the church and your organ tuner before entering the organ chamber. You should also seek your tuner's advice for safe ways to move around inside the organ and obtain access to enclosed divisions.
Never grab a pipe for support. Pipe metal is amazingly soft and the pipe will give way like a softened candle. In general do not touch or disturb the pipes. If you must, for example to clean out a dead moth, let the pipe cool from the heat of your hand before attempting to tune it. Pipes contain lead, so wear gloves or wash your hands afterwards. Tuning a pipe involves gently tapping a collar, scroll, flap or stopper up or down. For reeds, only adjust the tuning wire; never adjust the resonator. Use a proper tuning (not kitchen) knife so you can reach between ranks. For smaller pipes, balance the knife in your hand and use a gentle wrist action. Again, it may be best if your organ technician shows you how. Leave cone tuned pipes alone since these pipes are easily damaged during tuning and are usually quite stable.
But first you have to find the suspect pipe. A wand with a short length of tissue paper taped to its end can indicate wind motion if held near the mouth of the pipe or, if held over an open pipe, it should cause a speaking pipe to slightly change its pitch. This works best for larger pipes, so have your assistant play a lower note and then count up to the pipe in question. And remember, pipes can be arranged on chests either chromatically or diatonically. As you tune the pipe, keep an eye on the tuner until it indicates that the pipe is in tune. No organ is ever perfectly in tune, so don't get obsessive about getting it dead on. A visible tuner is also not a panacea. It can easily be confused by blower and wind noise, or it may dither as it tries to decide which harmonic to lock in on. In these cases, resort to having the tuner generate the correct tone and listen for, and eliminate beats. And don't be upset if pipes exhibit bad behaviour; it is in their nature. Improperly voiced flues may “wobble” and reeds may suddenly “fly off pitch” as you attempt to tune them. One just does the best one can.
I agreed to address the issue of how to use a visible tuner to tune harmonic corroborating ranks such as mutations and mixtures; so here goes. An experienced tuner tunes mutations and mixtures by listening for the harmonics in a reference pipe (usually a principal) and tuning against them. To do this with a visible tuner requires some theory. The most common harmonic stops are quints (Nazard 2 2/3' and its octave Larigot 1 1/3') and tierces (Tierce 1 3/5').
The quint (Latin: quintus meaning fifth) augments the third harmonic of the foundation stop that is drawn. Its confusing name comes from its pitch lying close to that of the foundation pipe an octave plus a fifth above, i.e., a 12th higher. As an example, the third harmonic of A 440 is 3 x 440 Hz = 1320 Hz. The note a 12th higher is E6 with a frequency of 1318.51 Hz. Calculations show this to be a difference of two cents. So a quint is simply tuned two cents sharp compared to what the tuner indicates. A note: The Pano Tuner actually allows you to enter 1320 Hz (or 3 x whatever A is at the temperature you're tuning at) as your reference pitch for A4 allowing you to tune the quint directly as the tuner indicates. Most other tuners will reject this value as being ridiculously out of range.
The tierce (Latin: tertius meaning third) augments the fifth harmonic of the foundation stop. Its name comes from its pitch lying close to that of a pipe two octaves plus a third above, i.e., a 17th higher. The fifth harmonic of A440 is 5 x 440 Hz = 2200 Hz. The note a 17th higher is C#7 with a frequency of 2217.46 Hz. This is a difference of almost 14 cents, so the tierce is tuned 14 cents flat compared to the tuner's indication.
Tuning mixtures is a messy affair. Fortunately, except for the Sesquialtera, which includes the tierce, almost all other mixtures include only the quint and its octaves. Mixtures are confusing because as you go up the scale, the pitches periodically “break back” to a lower pitch. You will recognize this point when the pipes suddenly go from short to tall. Also, when a single note is played, two, three or four pipes will sound simultaneously. Your first job is to silence all the pipes except for the one being tuned. This is done by inserting a “mop,” a pipe cleaner available in various diameters in craft stores. Say for example that you are tuning middle C (C4) on the keyboard and the tuner indicates that the pipe you are tuning is C5, C6 or C7, then tune that pipe to the tempered scale as indicated by your tuner. On the other hand, if it indicates that the pipe is G5, G6 or G7, Then you are tuning a quint and you need to tune it to the harmonic by making it two cents sharp compared to the tuner's indication. This sounds simple but in practice tuning the many squealers (short, high pitched pipes) in a mixture can be frustrating since sometimes it is hard for you or the tuner to accurately ascertain the pitch of these pipes. And the collar on a small pipe can be extremely sensitive to the smallest tap of the tuning knife causing them to sometimes go way off into “tuning never, never land.” So we wish you good luck and above all, “Do no harm.”
Image Captions:
Image 1: The well lit stairs and a hand rail allow the author to enter Casavant Opus 400 safely. Before its resurrection by Grant Smalley in 2010, access was gained via cleats screwed to one of the pipes of the Double Open Wood 32 seen on the right. With (tuning) knife clenched between one's teeth, one felt like a pirate boarding a ship. (Photos: Linda Anne Baker)
Image 2: So, which pipe needs tuning? These few hundred pipes of the REC(IT) DEVANT represent but a fraction of the 3100 pipes in the organ. The interior of an organ can appear intimidating. The key is to move carefully and deliberately and don't step on the small pipes! By the way, note that these pipes are arranged diatonically.