THEORY OF 3JCN MUSIC NOTATION
Definition: A chord is the combination of 3 or more notes which are arranged in vertical direction (needs softwares). To show chords in classical music with or without duration, we stack notes on top of notes:
For example: Chord C major 4g 5g
If we do not need softwares to write music, then we can write notes in a horizontal squared bracket. For example: [3a 4c 4e], [4c e g b]2,...
Every chord has certain characteristics, which include:
- Number of notes (3 notes = triad ; 4 notes = tetrad ; 5 notes = pentad ; 6 notes = hexad ...)
- The scale degree of the root note or the bass note (tonic, supertonic, mediant,...)
- Types of intervals (seconds, thirds, fourths,...)
- Chord quality (major, minor, augmented, dominished)
- When the bass is the root note, the chord is not inverted (ex: triad C = [ceg] root note is note C)
- when the third is in the bass, the chord is inverted (first conversion: [egc] root note is the third note)
- when the fifth is in the bass, the chord is inverted (second conversion: [gce] root note is the fifth note)
1. Tertian triads: Tertian triads can be described as a series of three notes. The first element is called the root note of the chord, the second note is called the "third" of the chord, and the last note is called the "fifth" of the chord. These are described below:
- Chord name Component intervals Example Chord symbol
- major triad major third perfect fifth [ceg] Do-Mi-Sol C, CM, Cma, Cmaj, CΔ
- minor triad minor third perfect fifth [c-eg] Do-Mi flat-Sol Cm, Cmi, Cmin, C-
- augmented triad major third augmented fifth [ce+g] Do-Mi-Sol sharp C+, C+, Caug
- diminished triad minor third diminished fifth [c-e-g] Do-Mi flat-Sol flat Cm(♭5), Cº, Cdim
Seventh chords may be thought of as the next natural step in composing tertian chords after triads. Seventh chords are constructed by adding a fourth note to a triad, at the interval of a third above the fifth of the chord. This creates the interval of a seventh above the root of the chord. There are various types of seventh chords depending on the quality of the original chord and the quality of the seventh added.
Five common types of seventh chords have standard symbols. The chord quality indications are sometimes superscripted and sometimes not (e.g. Dm7, Dm7, and Dm7 are all identical). The last three chords are not used commonly except in jazz.
Chord name Component notes (intervals) Chord symbol
diminished seventh minor third diminished fifth diminished seventh Co7, Cdim7
half-diminished seventh minor third diminished fifth minor seventh Cø7, Cm7♭5, C-7(♭5)
minor seventh minor third perfect fifth minor seventh Cm7, C−7, C−7
minor major seventh minor third perfect fifth major seventh Cm(Maj7), C−(j7), Cm♯7,
dominant seventh major third perfect fifth minor seventh C7, C7, Cdom7
major seventh major third perfect fifth major seventh CMaj7, CMA7, CM7,
CΔ7, Cj7, C+7
augmented seventh major third augmented fifth minor seventh C+7, C7+, C7+5, C7♯5
augmented major seventh major third augmented fifth major seventh C+(Maj7), C+MA7,
CMaj7+5, CMaj7♯5, C+j7, CΔ
harmonic seventh just major third just perfect fifth harmonic seventh (approx.) C7, C7
Chord symbols (in blue color) are written right above notes in the song.