Basic chord types
The above chords, despite their differences, share the same harmonic function and can be used interchangeably.
Major chords
Major seventh chord on C i.e. CΔ7
A major seventh chord contains the notes:
- root, 3, 5, M7, (9).
The symbols M7 and Δ7 have the same meaning as maj7 or just Δ. Often melody notes or other pitches influence an improviser's choice of chord types. For example, if the melody note is the root of the chord, including a major seventh can cause dissonance.
Major sixth chord on C i.e. C6
A major sixth chord contains the notes:
- root (often omitted), 3, 5, 6.
Major 6/9 chord on C i.e. C6/9
A 6/9 chord (C6/9 or C6add9) contains the notes:
- root (often omitted), 3, 5, 6, 9.
Lydian chord on C i.e. CΔ♯11
A Lydian chord (CΔ♯11) contains the notes:
- root (often omitted), 3, 5, M7, (9), ♯11 (13).
The Lydian chord has a strange quirk, where if the root is put both above and below the augmented eleventh it creates an unpleasant dissonance of a tritone. This is not usually a problem in a jazz context, as chord-playing musicians often omit the root.
The interval of the sixth is used, even though it is described after other compound intervals and perhaps should also be a compound interval (i.e., 13th). However, a convention in jazz dictates that when describing the major sixth, generally use the simple interval, i.e., 6 is often used instead of the compound interval, i.e., 13. This helps avoid confusion with the dominant thirteenth chord.
Basic dominant chords
The term basic can be used to describe dominant chords based on the major scale.[citation needed] In many instances, dominant chords written as basic chords (e.g., C13) can substitute for more complex chords, as long as they remain part of the same group (i.e., dominant chords) and do not clash with the melody notes.
Dominant chords are considered to sound unstable in classical music harmony contexts, and so in a classical piece, these chords often resolve down a perfect fifth or up a perfect fourth (e.g. C7 tends to resolve onto chords based on F, such as F major or F minor). However, in a jazz context, particularly in music from the 1940s bebop era and later decades, dominant chords were no longer treated as "unstable" chords. Some bebop tunes use a dominant chord as the tonic chord and also use dominant chords for the chords that would typically be minor chords in a classical piece or a swing arrangement. For example, while a classical piece and a swing arrangement might use the following chord sequence in the key of C major: "C – Am – Dm – G7", a bebop bandleader might reharmonize the same progression as "C7 – A7 – D7 – G7", making a sequence of dominant seventh chords, so long as the new dominant chord harmonies were compatible with the tune's melody. For more details, see chord progression.
Many of the chordal alterations used in jazz are derived from minor scale modes, as opposed to the major scale modes. (See musical mode.) If the performer retains the 13th in the chord and/or avoids playing a ♭13th, it can be substituted for a C13♭9. Likewise a C9 can often be substituted for a Cmaj9♯5, as long as the 9th is retained or the ♭9th and ♯9th is avoided.
Dominant seventh, ninth, and thirteenth chords on C i.e. C7, C9, and C13
A dominant seventh chord contains the notes:
- root (often omitted), 3, 5 (often omitted), 7, (9), (13).
A dominant ninth chord (C9) contains the notes:
- root (often omitted), 3, 5 (often omitted), 7, 9, (13).
A dominant thirteenth chord (C13) contains the notes:
- root (often omitted), 3, 5 (often omitted), 7, (9), 13.
This symbol is often used if the 13th is found in the melody.
Sus chord on C i.e. Csus4
A sus, or suspended, chord (C7sus4) contains the notes:
- root, 4, 5, 7, (9), (13).
Minor seventh chords
Minor seventh, ninth, eleventh, and thirteenth chords on C i.e. Cm7, Cm9, Cm11, Cm13
A minor seventh chord (C−7, Cmin7, Cmi7, or Cm7) contains the notes:
- root, ♭3, 5, 7, (9), (11), (13).
A minor ninth chord (C−9, Cmin9, Cmi9, or Cm9) contains the notes:
- root, ♭3, 5, 7, 9, (11), (13).
A minor eleventh chord (C−11, Cmin11, Cmi11, or Cm11) contains the notes:
- root, ♭3, 5, 7, (9), 11, (13).
A minor thirteenth chord (C−13, Cmin13, Cmi13, or Cm13) contains the notes:
- root, ♭3, 5, 7, (9), (11), 13.
Complex dominant chords
Augmented seventh chord on C i.e. C7(♯5)
Complex dominant chords can be voiced in a great variety of ways, including building the chord on the 3 or 7 (minor seventh). They usually, but not always, resolve to a chord built on an interval a fifth down from the root. Utilizing a tritone substitution, a dominant chord may resolve down a half-step instead. It is not uncommon to express the alteration (usually ♯9, ♭9, or ♯5) in the melody. For expediency, musicians may use the abbreviation "alt"—as in C7alt—to describe the family of dominant chords with altered tones (including the ♭5, ♯5, ♭9, ♯9, ♯11, or ♭13). Notably, all altered tones mentioned above, along with the 3 and ♭7, are present in the melodic minor scale whose root is a half-step above the root of the alt chord (i.e., E♭ melodic minor for D7alt). In other words, the altered scale is the seventh mode of the jazz minor scale. This scale is commonly used to improvise over an altered dominant chord. In the section on basic dominant chords, it was noted that the perfect fifth is often omitted. By altering it with a diminished fifth (♭5) or augmented fifth (♯5), extra tension and dissonance is added, which strengthens the resolution to the I chord.[6]
Dominant ♭9/♭5, Dominant ♯9/♭5, Dominant ♭9/♯5, Dominant ♯9/♯5 chords on C i.e. C7(♭9♭5), C7(♯9♭5), C7(♭9♯5), C7(♯9♯5). All of these chords can be written as C7alt.
A dominant ♭9/♭5 chord (C7(♭5♭9)) contains the notes:
- root (often omitted), 3, ♭5, 7, ♭9.
A dominant ♯9/♭5 chord (C7(♭5♯9)) contains the notes:
- root (often omitted), 3, ♭5, 7, ♯9.
A dominant ♭9/♯5 chord (C7(♯5♭9)) contains the notes:
- root (often omitted), 3, ♯5, 7, ♭9.
A dominant ♯9/♯5 chord (C7(♯5♯9)) contains the notes:
- root (often omitted), 3, ♯5, 7, ♯9.