In tonal Western classical music, the most frequently encountered chords are triads, so called because they consist of three distinct notes: the root note, a third above the root and a fifth interval above the root. Further notes may be added to give tetrads such as seventh chords (the most commonly encountered example being the dominant seventh chord) and added tone chords, as well as extended chords and tone clusters. Triads commonly found in the Western classical tradition are major and minor chords, with augmented and diminished chords appearing less often. The descriptions major, minor, augmented, and diminished are referred to collectively as chordal quality. Chords are also commonly classified by their root note—for instance, a C major triad consists of the pitch classes C, E, and G. A chord retains its identity if the notes are stacked in a different way vertically; however, if a chord has a note other than the root note as the lowest note, the chord is said to be in an inversion (this is also called an "inverted chord").
Δ is sometimes used for major, instead of the standard M, or maj,
− is sometimes used for minor, instead of the standard m or min,
+, or aug, is used for augmented (A is not used),
o, °, dim, is used for diminished (d is not used),
ø, or Ø is used for half diminished,
dom is used for dominant 7th
alt is used in jazz to indicate an altered dominant seventh chord (e.g., flat 9 and/or # 11)
7 is used for dominant 7th
9 is used for a ninth chord, which in jazz usually includes the dominant 7th as well
13 indicates that the 13th is added to the chord. In jazz, when a number higher than 9th is used, it implies that other lower numbers are played. Thus for A13, a pianist would play the 3rd, the 7th, 9th and 13th (the 11th is normally omitted unless it is sharpened. Roots and fifths are commonly omitted from jazz chord voicings).
sus 4 indicates that the third is omitted and the fourth used instead. Other notes may be added to a - Sus 4 chord, indicated with the word "add" and the scale degree (e.g., A sus 4 (add 9) or A sus 4 (add 7)).
/C♯ bass or /C♯ indicates that a bass note other than the root should be played. For example, A/C♯ bass indicates that an A Maj triad should be played with a C♯ in the bass. (Note: in some genres of modern jazz, two chords with a slash between them may indicate an advanced voicing called a polychord, which is the playing of two chords simultaneously--e.g., F/A would be interpreted as an F Major triad played simultaneously with an A Maj triad, that is the notes "F, A, C" and "A, C♯, E". To avoid misunderstanding, the "/C♯ bass" notation can be used).
5 in rock, hard rock and metal indicates that a power chord should be played. A power chord consists of the root and the fifth, possibly with the root doubled an octave higher. Thirds and sevenths are not played in power chords. Typically, power chords are played with distortion or overdrive.
Unusual chords can be indicated with a sequence of scale degrees and indicated additions or omissions (e.g., C7 (no 5th add 9) or F9 (no 7th add 13)).
Chord
https://en.wikipedia.org/wiki/Chord_(music)
In tonal Western classical music, the most frequently encountered chords are triads, so called because they consist of three distinct notes: the root note, a third above the root and a fifth interval above the root. Further notes may be added to give tetrads such as seventh chords (the most commonly encountered example being the dominant seventh chord) and added tone chords, as well as extended chords and tone clusters. Triads commonly found in the Western classical tradition are major and minor chords, with augmented and diminished chords appearing less often. The descriptions major, minor, augmented, and diminished are referred to collectively as chordal quality. Chords are also commonly classified by their root note—for instance, a C major triad consists of the pitch classes C, E, and G. A chord retains its identity if the notes are stacked in a different way vertically; however, if a chord has a note other than the root note as the lowest note, the chord is said to be in an inversion (this is also called an "inverted chord").
Additional Chord Forms
Chord Function
Chord Technique
Additional chord text interpretation
Δis sometimes used for major, instead of the standardM, ormaj,−is sometimes used for minor, instead of the standardmormin,+, oraug, is used for augmented (A is not used),o,°,dim, is used for diminished (d is not used),ø, orØis used for half diminished,domis used for dominant 7thaltis used in jazz to indicate an altered dominant seventh chord (e.g., flat 9 and/or # 11)7is used for dominant 7th9is used for a ninth chord, which in jazz usually includes the dominant 7th as well13indicates that the 13th is added to the chord. In jazz, when a number higher than 9th is used, it implies that other lower numbers are played. Thus for A13, a pianist would play the 3rd, the 7th, 9th and 13th (the 11th is normally omitted unless it is sharpened. Roots and fifths are commonly omitted from jazz chord voicings).sus 4indicates that the third is omitted and the fourth used instead. Other notes may be added to a -Sus 4chord, indicated with the word "add" and the scale degree (e.g., A sus 4 (add 9) or A sus 4 (add 7))./C♯ bassor/C♯indicates that a bass note other than the root should be played. For example, A/C♯ bass indicates that an A Maj triad should be played with a C♯ in the bass. (Note: in some genres of modern jazz, two chords with a slash between them may indicate an advanced voicing called a polychord, which is the playing of two chords simultaneously--e.g., F/A would be interpreted as an F Major triad played simultaneously with an A Maj triad, that is the notes "F, A, C" and "A, C♯, E". To avoid misunderstanding, the "/C♯ bass" notation can be used).5in rock, hard rock and metal indicates that a power chord should be played. A power chord consists of the root and the fifth, possibly with the root doubled an octave higher. Thirds and sevenths are not played in power chords. Typically, power chords are played with distortion or overdrive.