neumaRk — Chords¶
This document defines the syntax and semantics of chords in neumaRk, including:
- the dictionary of supported chord symbols;
- normalization of variants;
- bass handling;
- chord rhythm (implicit, explicit, mixed);
- optional chords.
Chords are contained in C) lines and may be used to describe both harmonic
content and its rhythmic realization.
1. Chord event¶
A chord event is a harmonic unit that may include:
- a chord symbol;
- an optional bass, or a bass only;
- a duration (implicit or explicit);
- duration modifiers.
A chord event may also represent:
- a rest (
r); - a repeated attack (
!).
Each chord event in neumaRk is an autonomous rhythmic entity, with either implicit or explicit duration.
A chord may include an explicit bass in the form of a slash chord
(e.g. A/B), or consist solely of a bass (e.g. /B).
In both cases, the event follows the same rhythmic rules as all other chords.
2. Chord symbol¶
2.1 General structure¶
The general form of a chord symbol is:
<root><quality>[<extensions>][/<bass>]
Where:
root∈{A B C D E F G}, with optional#orbaccidental (at most one);qualityidentifies the chord suffix;bassis optional and indicates a bass different from the root.
Examples:
C Dm GM F#7alt BbM13 C7/E
3. Chord dictionary¶
3.1 Triads¶
| Accepted input | Normalization |
|---|---|
| C | C |
| Cm, C- | C- |
| Co, Cdim | C° |
| C+, C5+, Caug | Caug |
| Csus2 | Csus2 |
| Csus4 | Csus4 |
3.2 Major chords (4 or more notes)¶
| Accepted input | Normalization |
|---|---|
| C6 | C6 |
| C69 | C69 |
| CM, CM7 | CΔ |
| CM9 | CΔ9 |
| CM13 | CΔ13 |
| CM#11, CM7#11 | CΔ#11 |
| CM9#11 | CΔ9#11 |
| CM13#11 | CΔ13#11 |
| CM+, CM#5, CM7#5, C+M7 | CΔ#5 |
3.3 Minor chords¶
| Accepted input | Normalization |
|---|---|
| C-b6, Cmb6 | C-b6 |
| C-6, Cm6, C-69, Cm69 | C-6 |
| C-7, Cm7 | C-7 |
| C-9, Cm9 | C-9 |
| C-11, Cm11 | C-11 |
| C-13, Cm13 | C-13 |
| C-M, CmM, C-M7, CmM7 | C-M |
3.4 Dominant chords¶
| Accepted input | Normalization |
|---|---|
| C7 | C7 |
| C9 | C9 |
| C13 | C13 |
| C7#11, C9#11, C13#11, C7b5 | C7#11 |
| C7b9 | C7b9 |
| C7alt | C7alt |
| C7#5, C+7 | C7#5 |
| C7#9 | C7#9 |
| C13b9 | C13b9 |
| C7sus, C9sus, C13sus | C7sus |
| C7susb9 | C7susb9 |
3.5 Diminished and half-diminished chords¶
| Accepted input | Normalization |
|---|---|
| Co7, Cdim7 | C°7 |
| CoM7, CdimM7, CoM | C°M |
| Cm7b5, Ch | Cø |
4. Chord rhythm¶
Note¶
The meaning of the dot (.) is specific to chord lines and does not match
its meaning in note lines.
Its semantics depend on whether it appears separated from the chord event
or inside an explicit duration.
4.1 Implicit mode¶
In the absence of explicit durations, chord rhythm is deduced.
Principle:
- chord events within a measure are counted;
- the measure duration is evenly subdivided;
- the dot (
.) extends the chord by its own duration.
Examples in 4/4:
| C Dm |
| C . . Dm |
| r C . Dm . D#o . Em |
In implicit mode, rhythm is not rendered, but is used for alignment.
4.2 Explicit mode¶
Chord duration may be specified inside parentheses:
C(4) Dm(8.) G7(8t)
The duration may include:
- a note value (mandatory);
- dots (
.), in standard notation, adding half of the value; tfor triplets (3:2 tuplets);- multipliers (
*n).
Special symbols:
r→ rest;!→ repeated attack (repeats the duration, not the symbol).
For the last chord in a measure, ^ creates a tie to the next measure.
With this notation mode, chord rhythm is rendered above the staff.
4.3 Mixed mode¶
Implicit and explicit modes may be combined within the same measure.
- only explicit durations are rendered;
- the remaining ones are deduced.
Example:
C Dm(8^)
5. Optional chords¶
An opening parenthesis starts a group of optional chords:
(C Dm G7)
6. General duration rules¶
- in case of conflict, explicit syntax always prevails;
- normalization does not alter semantics;
- implicit rhythm is deterministic.
This document defines the harmonic and rhythmic semantics of chord lines in neumaRk.