Note Names

Notes on an organ keyboard may be identified by one of three different schemes. Any of the three schemes may be used interchangeably, as they are all mutually unambiguous.

Consecutive Integers

Notes are identified by integers, where "1" indicates the lowest note on the keyboard (usually C, but not always). Notes are numbered contiguously and chromatically; i.e. if the lowest note is a C and there are consistently twelve semitones in each octave, then the C's are numbered 1, 13, 25, 37, 49, and 61.

Numbered Octaves

Notes are identified by a note name followed by an integer, the integer indicating the octave, with "1" indicating the lowest octave on the keyboard. "#" is used to indicate "black" keys. For example, the notest on most keyboard would start thus:
C1, C#1, D1, D#1, E1, F1, F#1, G1, G#1, A1, A#1, B1, C2, C#2, etc.

Formal grammar: ('A'|'B'|'C'|'D'|'E'|'F'|'G') ['#'] ('1'|'2'|'3'|'4'|'5'|'6'|'7'|'8')

Traditional Scheme

Each note above middle B is spelled with a single lower-case letter, with an optional '#', following by one apostrophe for each octave above the middle C octave; for example "c'", "d#''".
Each note in the octave starting at middle C is spelled with a single lower-case letter, with an optional '#'; for example "c", "d#".
Each note in the octave starting at tenor C is spelled with a single upper-case letter, with an optional '#'; for example "C", "D#".
Each note in the octave starting at low (8') C is spelled with a pair of identical upper-case letters, with an optional '#'; for example "CC", "DD#".
Each note in the octave starting at 16' C is spelled with a triplet of identical upper-case letters, with an optional '#'; for example "CCC", "DDD#".

Formal grammar: ('A'|'B'|'C'|'D'|'E'|'F'|'G')... ['#']

Summary for Typical Keyboard

Consecutive Integers	1	13	25	37	49	61
Numbered Octaves	C1	C2	C3	C4	C5	C6
Traditional Scheme	CC	C	c	c'	c''	c'''

Compasses

A compass (range of notes) is represented by one or more of the following, separated by commas:

a single note (as described above)
two single notes separated by a hyphen, which represents a contiguous range of notes

Examples: "G3", "C2-B2", "CC,DD,EE,FF,GG", "CC,DD,EE,FF-c''"