Seventh chords can be formed by adding a seventh to the root of a triad, creating a four-note chord (known as tetrachords). Varying the interval qualities can result in different sound quality.
This may appear daunting at first glance, but it’s actually quite straightforward: all it requires is taking a minor 7th and flattening its fifth to create this sound.
Major
Major seventh chords feature an ascending major seventh interval above their root note. They’re one of the most widely-used chords found in popular music genres like blues.
Like triads, seventh chords can also be constructed using thirds stacked upon thirds to form their shape. A Cmaj7 chord with close spacing resembles a snowperson with three parts – bottom, two middles and head – but has none of the usual notes at its heart.
Augmented seventh chords add tension and drama, making them an essential element in many jazz progressions. Based on diminished triads with the fifth tone flattened by one semitone to achieve their distinctive “augmented” quality, augmented sevenths may often be written Caug7 or C7(#5) on sheet music or lead sheets.
Minor
Minor seventh chords play an essential role in setting the tonic relationship for any progression and as tension-releasing substitutes for dominant seventh chords in blues progressions. They’re formed by stacking minor thirds, diminished fifths, and major seventh chords atop each root note of their chord’s composition.
Minor seventh chords can be identified by their low, chromatic notes – known as passing tones – which help alleviate dissonance in the chord. As they tend to be unstable chords with passing tones, passing tone chords will tend to resolve down by one step or less over time.
To create a minor seventh chord, start with a major triad and add one or more minor seventh notes to it. Use your key signature and any necessary accidentals when writing out this chord; label with roman numeral and open note head like so:
Dominant
The dominant seventh progression should become part of your chord vocabulary. You can either build it by adding a dominant seventh interval to an underlying chord, or play it solo; either way, its third and seventh create an upward tension that resolves downward to tonic – essential in creating strong cadences.
An easy way to build a dominant seventh chord is to start off by playing a major triad and add the flattened seventh. This creates a dynamic chord that is an integral component of blues music, featuring many variations such as dominant 7(b9) and the viio7 for creating doom or tension effects. Fender Play offers you everything you need to learn these chords as well as explore more of their distinctive qualities – sign up now for your free trial to start exploring this complex sound!
V7
Diminished 7th chords can give music an unsettling and dissonant tone by creating feelings of doom, tension and fear. They are non-diatonic because they do not include the sixth interval (double-flatted B).
To construct a V7 chord, draw its root onto a staff and add notes a third, fifth and seventh above it. If it is in a major key, write any accidentals from its key signature on those three notes; otherwise label each note with roman numerals to identify their quality if playing minor key chords.
Note that chordal sevenths always resolve downward stepwise due to their origin as accented passing tones; this makes them an effective replacement for dominant (VI7) chords.