ZylBlog | Music

“What is the difference between a rank and a stop?”

This is a question often asked, and often not answered very well. I’ll do my best.

Straightforward: A rank is a set of pipes, and a stop is the selector for a set/sets of pipes.
This means, when you pull a stop, you are indicating which ranks you want used. There are some complications following straightline thinking, and I will attempt to describe them.
To have a full rank, you need at least 61 pipes (because the average organ keyboard has 61 keys). Some stops might be limited to less than 61 notes, but this is something you’ll either have to bug me to write about or learn on your own. (Side note, “Tenor C”, or “Tenor” stops usually stop short with an octave of keys left in the bass).

Let’s pretend we have an 85 pipe trumpet rank.
If there are 61 keys, where do the extra go? We have many possibilities, and it’s all based on the pitch (not tone) of the pipe.
We can have a 8ft stop, which plays everything at the octave played on the keyboard.
If we wanted a 4ft stop, we would need 12 more pipes to play one octave higher.
If we wanted a 16ft stop, we would need 12 more pipes to play one octave lower. And so on an so on for 128ft, 64ft, 32ft, 2ft, 1ft, etc.

One common issue assuming that the statements are above are true, and then examining your organ is that sometimes the stops themselves, even on the same ranks, are called different things. (Eg: On the same rank, you may have a 4ft “Clarinet” and an 6ft “Trumpet” stop, which work on the same ranks, but because of where the typical pitch is for the instruments they have been modeled after we can call them different things. In my opinion: this is just confusing.)

Also, stops include mechanical features which do not create noise on their own, but add effect or modify tones. Mechanical stops include things such as octave couplers (to move everything an octave up or down), pedal to great, great to swell, swell to great, great to pedal, and other variants as well as tremulants, presets, and much more.

I wish I had a picture for this.