Seventh chords form the backbone of jazz harmony. These chords make up most of the repertoire, as well as being integral parts of accompanying soloists in comping arrangements.
Seventh chords are constructed from triads with the addition of an interval (a note three tones higher) above their root note. There are five varieties of seventh chords: Major, Dominant, Minor, Diminished and Half-Diminished.
Major Seventh
The major seventh chord is an increasingly popular choice in jazz and has an attractive sound that lends itself well to jazz compositions. Additionally, its use can be found across rock music and pop; however, heavier styles such as blues or funk tend to avoid it altogether.
To create a major seventh chord, all that’s required is drawing its root on a staff and adding notes that are thirds, fifths and sevenths above it. You can then adjust these notes according to its key signature or any accidentals that may apply.
Noting the various symbols jazz musicians use to represent chords is important when playing jazz, as different musicians may use different variations for Cmaj7 chord. While one musician may write it as C or even Cm. Being familiar with all these variations will ensure smooth communication on gig days!
Dominant Seventh
Dominant seventh chords differ significantly from major seventh chords in that they tend to sound dissonant and unsettling when played alone; great jazz musicians understand how best to use these chords when used as part of a larger context.
Dominant sevenths are chords composed of minor triads with an added flattened seventh to their root notes to make them non-diatonic. Their chord symbol usually features just numbers such as C7, G7 or D7 to identify this non-diatonic sound.
Jazz musicians use chords like these frequently when comping, or providing harmonic support for soloists. By employing these chords in comping, they can add tension and drama that really brings your accompaniment alive.
Minor Seventh
As a jazz musician looking to read chord charts, it is crucial that you become acquainted with the five common seventh chord qualities used across different styles and music genres, from classical through to modern (or “modal”) jazz.
To construct a minor seventh chord, all that’s needed is building a major triad and adding a flattened seventh. However, unlike with dominant sevenths, minor seventh chords require you to consider which scale you are using when building them.
As with other chords, C mixolydian scale can be useful when creating minor seventh chords; alternatively you could opt for any minor scale of your choosing. As is the case with all chords, root and quality must first be identified (inversion will be covered later). Finally, to create the “distant” sound of minor seventh chords it’s necessary to consider how a flattened seventh fits within that scale; this creates what makes them distinct from major seventh chords which tend to sound more secure and complete.
Half-Diminished Seventh
In jazz, a half diminished chord is a triad with a flattened seventh. This chord can easily fit into 2-5-1 progressions and therefore is widely used.
This chord features a minor third beneath a flattened seventh note and an undivided diminished triad above, creating a more complex chord than major seventh but less complex than full diminished. Additionally, this is often used to accompany jazz standards for minor ii, v and i parts.
dim7 chords stand out because their structure derives from melodic minor scale notes on their way up, but does not change notes when moving down the scale. As a result, these chords are sometimes known as leading tone chords.
Dim7 chords are unique because they’re completely symmetrical: built up of stacks of minor thirds connected by two augmented fourths/diminished fifths (tritones). This allows them to resolve virtually anywhere on the keyboard or guitar fretboard.