Yesterday in church I played a unique little organ piece by Johann Sebastian Bach. Unique because it asked me to use the sequialtera.
The sesquialwhat? You might be asking. Our associate pastor wondered that very thing.
Sesquialtera literally means "relating to or denoting the ratio of 3:2, as in the interval of a fifth." (I know this because I looked it up.) Basically if you played a C, you would hear a G instead. It's an odd sounding stop, indeed, but that really isn't the point of this installment.
What made Bach's piece odd was that he specifically asked for the organist to use one at the beginning of his setting of "Ein feste Burg" aka "A Mighty Fortress [is our God]" and there are in fact two reason this is unusual.
The first is that Bach almost never indicated which stops he wanted the organist to use, beyond occasionally asking for "full organ" (organo pleno). The second is that this a really weird stop to be asking for by itself, and the lower voice should be supplied by a bassoon stop, which is also quite colorful. It is a very interesting combination.
We are told, however, that Bach's choice of stops often surprised his contemporaries, who thought they wouldn't sound very agreeably, and were astonished to find how well Bach knew how to find pleasing and interesting combinations.
It is also theorized that Bach wrote the piece to show off the newly improved church organ at his second church, which happened to have added these stops, and he wanted to take advantage of this rather interesting and recently acquired sound.
The reason I am mentioning all this, however, is because this fall I am writing several blogs to help persons who are either young or beginning organists, or people who are basically pianists playing the organ and are not familiar and/or comfortable with the instrument. Specifically, this group of blogs has to do with the topic of organ registration, namely, what to do with all of those knobs!
For those of you entrusted with an organ, and feeling somewhat intimidated by it, let me suggest that while that is perfectly understandable, I hope you'll also realize what an opportunity you have to explore all of those knobs. So many possibilities exist in this instrument!
Including some right under your nose. Let me make a clean breast of something. In 2004, when I was still a piano major in graduate school, I was just beginning to take an interest in the pipe organ. I played Bach's piece for the first time at my church in Baltimore. A year later, I moved to Illinois, and was chagrined to discover that the organ there had no sesquialtera. I had grown rather fond of that queer sounding stop; I didn't use it a whole lot, but it was awfully flavorful when I did.
It was about 10 years later, during which I gradually took more and more of an interest in the music of the organ, and began reading books about organ registration, going to online resources, basically anything I could find, that I found something curious, which also made me feel foolish. That stop I had been missing for years was actually there!
A sesquilatera is something known as a "compound stop." The one at my former church was marked "sesquilatera II." The roman number "two" means that two different ranks of pipes are joined together to make up this stop, and that you can access both of them joined together by pulling this single stop knob.
On the other hand, it turns out you can make your own sesquialtera by drawing two other stops, known as the Tierce, and the Nazard. Pulling these stops both out will give the same result. Too bad it took so many years to find that out!
In other words, some stops can actually be created by building them from the right combinations of other stops. This is what is so fascinating, and, for better or worse, sometimes takes a while to find out.
I'll back the truck up for a few weeks and talk about more basic ideas for organ registration to help anyone who is getting started, but I hope you find this sufficiently interesting to start experimenting with the stops on your organ, which, granted, can be dangerous if you do it on Sunday morning without checking the results during practice, but can lead to some pretty interesting results.
As for the old sesquialtera, I happen to have a recording of it from my old church. It is part of a series of articles I did about the organ back in 2004, and which included recordings of every stop available on that organ. Here it is: [listen]
I tried to have a little fun with the various stops, so if you think you might be going a little crazy, let me assure you, that really IS the opening of "smoke on the water" on the sesquialtera.
Is that enough to make you want a sesquialtera of your own? It helps if your stop knobs have fractions on them; we'll discuss that in a few weeks.
In the meantime, here is a recent recording from the organ in Illinois, of J. S. Bach's Ein feste Burg, complete with the opening combination of sesquialtera and bassoon: