Notation

There are many different forms of musical notation in xenharmony. This page will serve as an introduction to some of the concepts found in xenharmonic notation, and some of the more common types. Note that this does not cover interval naming systems with no notational counterpart. Notation systems are usually designed for consistent tuning systems such as regular temperaments, or approximately consistent tuning systems.

Notation concepts

Nominals

Nominals represent the basic notes of a scale that serves as a basis for the system being notated. Nominals are not strictly necessary (any consistent tuning system technically has a notation that works with only accidentals) but are convenient for understanding the melodic structure of a system being notated. In standard diatonic notation, the nominals are C, D, E, F, G, A, and B, which represent the seven notes of the C major scale.

Accidentals

Accidentals are the term for any symbol representing an alteration to a nominal. In standard notation, the # accidental raises a note by a chromatic semitone, and the b accidental lowers by a chromatic semitone. Microtonal notation systems usually add new accidentals, rather than changing the set of nominals. For example, the ^ and v accidentals (arrows) raise and lower by an edostep.

Microtonal notations

Diatonic notation

This page covers commonly accepted extensions to standard diatonic notation used in microtonality. The 7 nominals C, D, E, F, G, A, B form the C major scale, and # and b raise and lower notes by a chroma.

KISS notation

KISS notation generalizes the principles of diatonic notation to any arbitrary MOS, involving alphabetic note naming based on the MOS in question, and accidentals based on the difference between that MOS' step sizes. KISS notation refers to a family of closely-related notation schemes.

Standard KISS notation

KISS notation, in its standard form, uses numbers to name notes, but the standard # and b symbols as accidentals, and places the treble and bass clefs around the middle note as they are in diatonic notation.

Quasi-diatonic MOS notation

Quasi-diatonic MOS notation uses letters as nominals, starting from A at 440Hz as the final note of the darkest mode of the scale, much as A is the final note of the Locrian scale before it repeats at B, uses standard accidentals, and has a custom system of clefs corresponding to each nominal.

Diamond-MOS notation

Diamond-MOS notation aims to disambiguate itself from diatonic notation by using different nominals (from J onwards), different accidentals (& = #, @ = b), and a custom clef system that makes it visually apparent where J is in different octaves on the staff and what MOS is being used.

Just notation systems

Conventionally, just intonation notation systems rely on a series of accidentals that move up or down a "formal comma" for each prime from a basic Pythagorean interval.

Common formal commas include 81/80 for 5 (the difference between the classical and diatonic major thirds), 64/63 for 7 (the difference between the diatonic and septimal major thirds), 33/32 (the difference between the perfect fourth and 11th harmonic) for 11, and 513/512 (the difference between the diatonic minor third and 19th harmonic) for 19.

	FJS	HEJI	Neutral FJS	Ben Johnston
Basic diatonic	Pythagorean			Zarlino
7	64/63			36/35
11	33/32		sqrt(243/242)	33/32
13	1053/1024	27/26	sqrt(507/512)	65/64
17	4131/4096	2187/2176	4131/4096	51/50
19	513/512			96/95
Accidentals used	Numbers that stack multiplicatively, with otonal intervals all inflected in the same direction	A selection of symbols	Numbers that stack multiplicatively, with otonal intervals all inflected in the same direction	Numbers and inverted numbers, with otonal intervals all inflected in the same direction, except for the syntonic comma (+/-) and prime 11 (^/v),
Other notes	All formal commas are derived systematically. Each prime harmonic is inflected from the simplest Pythagorean interval within 54.1 cents (or 57.8 cents).		Similar to FJS, but includes "dicot" intervals for more intuitive notation of neutral intervals. Each prime harmonic is inflected from the simplest Pythagorean or neutral interval within 33.4 cents.	Uses Zarlino diatonic as nominals, 36/35 as the accidental for 7, and 96/95 as the accidental for 19.

Color notation

Color notation is a notation system that uses a series of syllables to notate just intervals, fully replacing the standard interval qualities. An interval's degree is determined from its mapping to 24edo.

Syllable	Intervals	Notes
la	Raised by a chromatic semitone	Not used, # is used instead
sa	Lowered by a chromatic semitone	Not used, b is used instead
wa	3-limit, no alterations	3-limit, no alterations
ru	7 under, generally supermajor	+64/63
yo	5 over, generally ptolemaic major	-81/80
gu	5 under, generally ptolemaic minor	+81/80
zo	7 over, generally subminor	-64/63
lu	11 under	-33/32, +729/704
lo	11 over	+33/32, -729/704