Chord

Chord patterns, spelled chords, inversions and the reviewed chord catalog. More...

Collaboration diagram for Chord:

Namespaces
namespace	MCC::Chords
	Reviewed catalog of named chords stored in program memory.

Classes
class	MCC::Chord
	A chord pattern spelled from a root note name. More...
class	MCC::ChordPattern
	Root-independent chord structure: up to seven ascending tones within two octaves. More...

Detailed Description

Chord patterns, spelled chords, inversions and the reviewed chord catalog.

MCC::ChordPattern stores up to seven tones within two octaves as diatonic steps and semitones above the root, built at compile time from a chord formula such as "1 3 5 b7 9". MCC::Chord spells a pattern from a root MCC::NoteName and voices its inversions in close position. MCC::Chords holds the named catalog with symbols in program memory, read through Foundation::Utils::Flash, and MCC::Chords::FromScale() lists every catalog chord whose tones are written in a scale, as the historical ChordPool did. See Music-Domain Specification (SPEC-CHD-*).

const MCC::Chord e9 =
    MCC::Chords::Make(MCC::NoteName(MCC::Letter::E), MCC::Chords::Id::DominantNinth);
MCC::NoteName ninth = e9.ToneAt(5);                    // F#
 
MCC::Chords::ScaleChord pool[64];
size_t count = MCC::Chords::FromScale(cMajorScale, pool, 64);

Available when MCC_CHORD is defined. Requires the Scale module and Foundation 2.0.10 or newer.

Catalog and Provenance

Identifiers are stable. Entries 0-22 come from the historical OLD MCC .Chord files under ChordFlash/ChordDefinitions, read with their interval lists and modifiers applied; the Arduino copy and the older MusicCompositionCore copy carry the same entries. Their NoteLayout inversion masks were copied between chords and were not migrated: inversions are computed instead. Spellings are shown from C.

Id	Name	Symbol	From C	Provenance
0	Major		C E G	Legacy
1	Minor	m	C Eb G	Legacy
2	Augmented	aug	C E G#	Legacy
3	Diminished	dim	C Eb Gb	Corrected: legacy intervals duplicated Augmented
4	Sixth	6	C E G A	Legacy
5	Minor Sixth	m6	C Eb G A	Corrected: legacy used a minor sixth
6	Dominant Seventh	7	C E G Bb	Legacy
7	Major Seventh	maj7	C E G B	Legacy
8	Minor Seventh	m7	C Eb G Bb	Legacy
9	Half Diminished Seventh (Half Diminished, Minor Seventh Flat Five)	m7b5	C Eb Gb Bb	Corrected: legacy lacked the flat fifth
10	Diminished Seventh	dim7	C Eb Gb Bbb	Corrected: legacy lacked the flat fifth
11	Dominant Ninth	9	C E G Bb D	Legacy
12	Dominant Minor Ninth (Seventh Flat Ninth)	7b9	C E G Bb Db	Legacy
13	Major Ninth	maj9	C E G B D	Legacy
14	Minor Ninth	m9	C Eb G Bb D	Legacy
15	Dominant Eleventh	11	C E G Bb D F	Legacy
16	Major Eleventh	maj11	C E G B D F	Legacy
17	Minor Eleventh	m11	C Eb G Bb D F	Legacy
18	Dominant Thirteenth	13	C E G Bb D A	Revised: the eleventh is omitted, as is standard
19	Major Thirteenth	maj13	C E G B D A	Revised: legacy added a sharp eleventh; omitted
20	Minor Thirteenth	m13	C Eb G Bb D F A	Legacy
21	Suspended Second (Sus2)	sus2	C D G	Legacy
22	Suspended Fourth (Sus4)	sus4	C F G	Legacy
23	Minor Major Seventh	mMaj7	C Eb G B	New
24	Augmented Seventh (Seventh Sharp Five)	aug7	C E G# Bb	New
25	Added Ninth	add9	C E G D	New
26	Seventh Suspended Fourth	7sus4	C F G Bb	New
27	Power (Fifth)	5	C G	New

Names in parentheses are aliases accepted by MCC::Chords::Find(). ChordCatalogTests checks this table, uniqueness of identifiers, names, symbols, aliases and patterns, and spelling from all 35 roots with up to two accidentals. On AVR the catalog is emitted in .progmem.data.

Recognition of a chord from loose notes is not part of this module yet: a pitch-class set is often ambiguous (C6 and Am7 share their notes) and loses spelling, so it will be designed with the MIDILAR integration.