Keyboard Ranges

The ranges of keyboards for carillons and other tower bell instruments are shown in the "Technical data" section of site data pages in a "shorthand" format to avoid wordiness.  Although this may seem a bit confusing at first, you will probably become quite comfortable with it after looking at several different site data pages.

The format is described below as it applies to traditional baton keyboards for carillons.  However, it can also be applied to chimestands, electric keyboards, and indeed any device for playing musical notes by hand.  The minor variations of the format to fit these situations are described in the third section below.

Page contents:

Basic format

In its simplest form, a keyboard range specification looks like this:

     MlMh / PlPh  


The "MlMh" and "PlPh" parts show the ranges of the respective keyboards, where

In this simple form, it is assumed that

However, nothing is assumed about the possibility of missing notes within these ranges.  That question is covered elsewhere in the "Technical data" block.  (See also "Missing semitones", below.)

Furthermore, in this simple format it will always be true that if there are any pedals, then  Ml = Pl, i.e., all pedals are connected within the console to the corresponding bass notes of the manual keyboard.

Example 1:

   C C / C G 
would describe an instrument where the manual has a full multi-octave range from C-natural to C-natural (the number of octaves being implied by the number of bells) and the pedal has a range of one-and-a-half octaves from C-natural to G-natural.
In this example, as well as in the format illustration above, spaces were inserted for readability.  However, the format is quite usable without any spaces at all (e.g., CC/CG).

Full format

If any of the simple-format assumptions are inappropriate, then one or more pieces of this more complex format must be included to specify the keyboard(s) completely:



Example 2:

   G C 42 / C G 
would describe a 4-octave instrument with the old Dutch standard clavier of 3 1/2 octaves (G to C) on the manual and 1 1/2 octaves (C to G) on the pedal.  Determining the number of missing bass semitones (if any) requires comparing this specification to the total number of bells, which is not part of the ranges format.

Example 3:

   C C  / C C 25 
would describe a fully chromatic instrument because there are 2 full octaves in the pedals.  This would fit the GCNA standard 4 octave clavier, but might also describe a 3- or 5- or 6-octave clavier.

Since there is no "flat" character in most computer display fonts, the "sharp" version of all "black notes" is used, e.g. "A#" for B-flat.

Example 4:

   C C 49 / A#C 26 
would describe an instrument with 4 fully chromatic octaves on the manual and just over 2 octaves on the pedal, including a bass A# (B-flat) which is the only note not connected to the manual.  The bass B-natural must be missing from the pedal, and there must be 50 bells altogether.

Remember that most carillons are transposing instruments.  To know what pitch is actually produced when a given key is pressed, you must adjust for the transposition given in the "Technical data" section for the instrument.

Missing semitones:

The keyboard range specification is usually independent of the number of missing semitones in a particular instrument (if the number of bells is also ignored).  But it is important in determining which semitones (if any) are missing.  Semitones are counted with respect to the lower of "Ml" or "Pl", taking that note to be the tonic of a major scale.  Thus in Examples 1,2,3 above and Example 5 below, they would be figured with respect to C-natural; the first possible missing semitone would be C#, while the second would be D#.  In Example 4 above, the starting point is A#, so the first possible missing semitone would be B-natural, the second C#, and the third D#.  Note that the last of these (D#) is relative to the C-major scale, not to the B-flat-major scale; this is an extremely rare situation.

When range specification and number of missing semitones are considered together, this limits the possible values for the number of bells.  Considering the range in Example 1, above, if there are no missing semitones then the only possible numbers of bells are 25, 37, 49, 61 or 73.  If there is one missing semitone within that range, then the only possible numbers of bells are 24, 36, 48, 60 or 72.  And two missing semitones would permit only 23, 35, 47, 59 or 71 as possibilities for the number of bells.

Missing notes elsewhere in the range are explicitly identified in the "Remarks" section of the site data page for the instrument.  In a few instances where the highest semitone, a C#, is missing, "Mh" appears as "CD".


If there is no pedalboard (as in most chimestands and all electric actions), then "PlPh" appears as "NONE".

Example 5:

describes the Taft Memorial electric-action carillon in Washington, DC, which has just over 2 octaves on the manual plus a very heavy bass pitched a fourth lower than the next bell.  There is no pedalboard on this instrument.
For rings, which have no keyboards and are purely diatonic, then "MlMh" may appear as "ROPE".

For instruments which have a larger keyboard than is presently necessary (probably in anticipation of a future expansion), that can be shown by making "mm" be the total number of keys present (which would be greater than the total number of bells).  This would be done only if "mm" is not required for the more ordinary purpose defined above.  Regardless of that, such an anomaly should be explained in the Remarks block.

Added semitones:

Chimes are often more nearly diatonic than chromatic.  This is especially true for old American-made chimes.  Therefore it makes more sense to describe such instruments in terms of semitones added to a diatonic scale than in terms of semitones missing from a chromatic scale.  This does not affect the applicability of the keyboard range format described above, but it does affect how the semitone status is stated in the "Technical data" section for the instrument.  Such added semitones are explicitly identified in the "Remarks" section of the site data page for the instrument (at least if they are known).

Why is all this folderol necessary?

Or to put it more specifically, why do all of these variations in arrangements of notes of tower bells exist?  Why can't they be nicely standardized - like pianos, organs and other keyboard instruments?

Aside from the obvious answer of "history" (with the obvious parallel to historical organs, pianofortes, etc.), there are three major factors:  space, weight and money.  Those factors determine how large a set of bells (both numerically and weight-wise) can be put into an existing tower.  Or, conversely, they determine how big a tower must be built to house a planned set of bells. 

What is unusual about a tower bell instrument in comparison to other kinds of keyboard instruments is that the incremental cost of adding one bass note to a given range is vastly greater.  The pitch of a bell is inversely proportional to its inside diameter at the strike point; this is a linear relationship, exactly analogous to the relationship of the length of an organ pipe or piano string to the pitch of a note.  However, the weight is proportional to the cube of that diameter.  Using organ building terminology, scaling of organ pipes typically involves halving at about the 16th note of the scale, whereas scaling of tower bells involves halving at the 4th note of the scale - a drastic difference.  Besides, a carillon or a chime is located in a place where it isn't intended to be played with other instruments, which makes the concept of "concert pitch" generally irrelevant.

Therefore, omitting one rarely-used semitone near the bottom of the range can save a very large amount of money, weight and space, while retaining the impact of the deepest affordable bass note.  Alternatively, transposing upward can make it feasible to provide a fully chromatic instrument for less cost (in terms of money, weight and space) than a heavier instrument of the same range would require.  It's all a matter of balancing various significant values in a particular situation.

For a real-life display of just how much variability really exists in carillon keyboards, see the index to North American traditional carillons by keyboard range.  The number of different keyboard arrangements that exist in just this geographical region, where the art of the carillon encompasses less than a century, may astonish you.

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This page was created 1997/01/20 and last revised 2020/04/15.

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