More items will be added to this page. For now, here are the music director's remarks, as well as the written explanation of the new stop.
We are about to dedicate for service a new stop that has been added to our pipe organ. This is a happy moment because our musical offerings and celebrations will be made richer by the new sounds that this stop provides.
This new stop is a gift from Ed Abbe, and we are very grateful to him for his generosity and commitment to Saint Philip's. This organ stop will endure for generations to come. Ed, thank you very much for your gift to all of us.
The new stop is called a 2⅔' Twelfth, and it is playable on the lower keyboard, called the Great. Today's bulletin insert [see below] explains in some detail what the stop is and why it is useful. The stop consists of 58 pipes, one for each key. It is most useful for producing a unique solo voice, in combination with one or more other stops.
This new set of 58 pipes was designed, voiced, installed, and tuned by Czelusniak et Dugal. Bill Czelusniak is with us this morning, and I hope that you will welcome him and thank him for a job well done.
Bill, and his voicer Jon Van Houten, and his assistant Gary Smith have made numerous visits to our pipe organ to adjust the voicing of each of these new 58 pipes. This is a normal process, to play the stop extensively, to discuss how to adjust it for the better, and then to do so. Bill, with his team, has always been right there for us, focused on producing the best possible result. We are blessed with an excellent result, giving us a gorgeous set of new sounds.
Let us be thankful for Bill's expertise and dedication. Let us be thankful for Ed's generous support for our Saint Philip's, and for his love of music. Let us thank God for our spiritual home here in Saint Philip's, with its community of faithful servants celebrating our Lord's grace.
The new stop for our pipe organ is called a 2⅔' Twelfth. This new rank of pipes was made possible by a generous gift from Ed Abbe, to whom we express our gratitude. The design, installation, and voicing were carried out by Messrs. Czelusniak et Dugal, Inc., of Northampton.
This rank makes a unique sound when used in combination with one or more other stops; one would not use the Twelfth by itself. We will enjoy our new stop in a variety of combinations and musical settings. It is most noticeable when giving a solo line a very distinctive voice. For example, in this morning's prelude, we hear the solo line of a piece from a Couperin Mass, using the combination of the 8' Open Diapason (Principal) and the 2⅔' Twelfth. In the dedication piece by Bach, we hear an embellished hymn tune as a chorale prelude, on the combination of a soft flute, called an 8' Gedeckt, and the 2⅔' Twelfth. In the postlude, we hear a Buxtehude chorale prelude again employing the 8' Gedeckt and the 2⅔' Twelfth, with an accompaniment of fewer voices than the Bach. The new stop has uses in larger combinations as well, but there its effect is as a chorus member, not as a soloist.
An 8' stop means that the low C pipe is approximately 8 feet long from its mouth to its top, or that it functions as if this were so; this pitch is the same as the pitch heard from a piano, key for key. The pitch of an organ pipe is proportional to its length. For the 8' stop, the C pipe one octave above low C has a length of 4'. Similarly, the middle C pipe is yet another octave higher and has a length of 2'. The next C pipe has length 1', then 6", and finally 3" for the high C pipe. For a 4' stop, the low C pipe is 4' long, with the high C pipe being 1.5" in length. If both an 8' stop and a 4' stop are drawn (pulled out, ready to play), then playing any one key will sound two pipes simultaneously. Additional stops drawn will cause even more pipes to sound.
Why does a pipe organ have stops whose pitches differ for the same key played? Consider that when an instrument sounds a fundamental pitch, also called the first harmonic, there are additional quieter pitches above it called upper harmonics that sound at the same time. These are not usually heard as separate pitches, but they are there, and they color the sound. The strengths of the fundamental and its upper harmonics largely determine the characteristic quality of the sound. The second harmonic is one octave above the first harmonic (fundamental), corresponding to a pipe one half as long. The third harmonic is an octave plus a fifth, called a twelfth, higher, corresponding to the pitch of a pipe one third as long. The fourth harmonic is two octaves higher, corresponding to the pitch of a pipe one fourth as long. So it goes with each harmonic corresponding to the pitch of a pipe the next unit fraction as long as the length of the pipe of the fundamental pitch. A pipe organ is much like a sound synthesizer because one can draw combinations of stops that emphasize the various harmonics, altering the characteristic quality of the resulting sound.
Why does our Twelfth have a 2⅔' length pipe for low C? This is because the pipe of the proper length for its third harmonic would be one third as long, and one third of 8' is 2⅔'. This stop emphasizes the third harmonic above the fundamental (first harmonic). And, why is the name of the stop Twelfth? If one counts the number of white keys going up from the low C key to the next C and then the next G, there are twelve such white keys. The pitch of the first harmonic and the pitch of the third form an interval that is called a twelfth. This kind of reasoning about harmonics and pipe lengths is sufficient to explain all of the Arabic numerals that one sees with organ stops, including the mixed fractions such as 2⅔.
Some stops have Roman Numerals on them. One of our stops is called a Mixture III, and part of Ed Abbe's gift included refurbishing these pipes, and revoicing some that did not speak properly. The III means that there are three pipes for each note, and hence three ranks of pipes. For the low C of the Mixture on our organ, the lengths of the three pipes are 2', 1⅓', and 1'. There are other special properties of mixtures. For example, the pipes of the 1⅓' and 1' ranks would become so short, as one proceeds up the keyboard, that they would be exceedingly difficult to build, tune, or even hear. When a pipe would otherwise be too short, a longer pipe of lower pitch, usually one octave lower, is used instead. This shift to a longer pipe than one would expect is called a break. Not all Mixture III stops are the same. The ranks may start at different pitches, and they may break at different places. Some pipe organs have mixtures of up to X ranks, but II, III, and IV are most common. One does not use a Mixture by itself; it makes sense only in combination with other stops.
For our pipe organ, on the main manual, called the Great, we already have Principal stops of length 8', 4', and with the Mixture, we also already have Principal voices at lengths of 2', 1⅓', and 1'. Taken together, these correspond to the first, second, fourth, sixth, and eighth harmonics. Because we have added the 2⅔' Twelfth, we have the third harmonic as well. It is rather dry to say that we now can emphasize the third harmonic whenever we please. However, by listening to the new sounds that this affords, we sense a fuller palette of musical colors than before.
This tonal expansion provides enduring value to Saint Philip's, to the organ, and to our musical celebrations for the glory of God. We are most grateful for God's gifts, including this new stop, which will be enjoyed for generations to come.