The organ is a machine, and like most machines it runs well so long as it receives its routine maintenance. The most important aspect of this maintenance takes the form of regular tunings. The organ is tuned three or four times a year, and one of these tunings took place this past Monday. I thought it would be interesting for you to know a little bit about what goes in to it.
First of all, it’s a big job. Like the strings on a piano, every pipe must be tuned individually. Each separate sound on the organ, called a stop, has its own set of pipes, called a rank, one pipe for every key or pedal. Keyboard ranks on Trinity’s organ have 58 notes, and pedal ranks have 30 notes. Some stops (called mixtures) have two, three, or even four pipes for each note that combine (or mix) make up that stop’s particular sound. All told, Trinity’s organ has 26 stops with 30 ranks of pipes. This works out to about 1572 pipes, each of which must be tuned individually. As I say, it’s a big job.
Second, tuning the organ is a two-man job. One person (me) has to sit at the console and hold each individual note while another person (the tuner) goes up in the case—sometimes way up—and tunes each pipe. The different sounds on the organ are produced by different types of pipes, which are tune by different methods. Some pipes are wooden, and they are tuned by adjusting a rectangular stopper that rests in the top of the pipe. Other pipes, made of metal, are tuned by moving a cylindrical “tuning collar” (think of a soup can with both ends cut off fitted on the top of the pipe) that changes the length, and thereby the pitch, of the pipe. Other types of pipes are tuned by other methods; I will be happy to give the full lecture and demonstration to anyone who is interested.
Finally, it’s a tedious job. Some of the pipes are pencil sized or even smaller, and the tolerances of correct tuning might be some fraction of a millimeter. Also, it is extremely difficult to hear, really hear, the pitch when a shrill note–which is designed to soar over the sound of the full organ–is blaring right in your face. The tuner must possess not only a good a good ear, but he needs to have good mechanical skills to understand and deal with the organ’s many components. A measure of bodily courage is also helpful for climbing up, through, and around some pretty tight spaces in the case.
The two main factors that affect the tuning are temperature and humidity; fluctuations in those are what necessitate the tuning. Every so often, a pipe will slip out of tune to such a degree that an egregiously sour note results. Most of the time, however, the “out of tune-ness” is more subtle but more widespread; this causes the organ to sound sluggish and rough. The organ having been tuned this week, I think that the primary difference one will notice (barring any wrong notes perpetrated by its operator) will be a sleeker, cleaner sound.