Seventh chords can add another level of sophistication and open up more styles such as funk, bebop and jazz-blues.
A seventh chord can be defined as a triad with an added seventh note added on top. Each type of seventh has its own name and chord symbol; for instance, C dominant seventh has doubled root notes and a flattened seventh interval that falls half-step below the octave – its formula being 1-3-5-b7.
Major Seventh
A major seventh chord is the next most complex chord after triad, adding another interval at the top of its structure to produce an open sound and add tension. Jazz composer Wayne Shorter famously used this technique in his composition “Sway.”
Major sevenths can be found throughout modern music, particularly pop and soul genres; they even date back to romantic composer Claude Debussy’s “Claire de Lune.” Major sevenths provide a soothing quality compared to their dominant seventh counterparts which can cause dissonant tones.
Minor Seventh
Minor seventh chords might look intimidating at first glance, but they’re actually very easy to play on guitar. Simply combine three major triads with an added minor seventh to form these complex sounding chords.
Just like triads, seventh chords are stacked chords with close spacing that can be written melodically and harmonically. A seventh chord whose sounding notes appear across keys can be described by its “quality.”
A seventh chord’s quality can be determined by the distance between its root note and seventh note in a scale – for instance, chords whose roots are G and D can be described as major because the distance between its seventh note and root is a major third. Chords built using le (3 and 6) feature major triads with major sevenths; those composed using re and ti have diminished triads with minor sevenths.
Dominant Seventh
No matter what genre of music you play – from rock, blues or jazz – the dominant seventh is one chord you are sure to encounter. Consisting of root, major third and perfect fifth from any scale combined with an additional flattened seventh note from that same scale (it would typically appear written as C7), you will come across this chord often.
Dominant 7th chords can be heard everywhere from blues music to pop and R&B; even the Rolling Stones used one for their hit, “(I Can’t Get No) Satisfaction.” They offer strong stability yet contain an element of tension which leads to resolution.
Building a dominant 7th is easy on any note – simply take a minor seventh flat five (MM7) chord and reduce its seventh by half step (to Bb). This technique also makes a diminished seventh chord; sometimes this type of chord may even be called “half-diminished seven,” “suspended,” or even a suspended chord.
V Seventh
Though it may appear complex, the V seventh chord can be broken down quickly and easily. At its core, it’s just another major triad with an additional third added on top. Since all major keys share the same formula for major chords, you can use it regardless of key (ie if playing in C, you would replace its 7th note with B instead (C E G and B).
As with other seventh chords, dissonances associated with sevenths must be resolved to restore harmony; usually this involves moving towards the tonic tone while chordal sevenths typically resolve down by one step.
To build a seventh chord quality, draw its root on the staff and add all required accidentals from its key signature. This will produce either a major triad with major seventh, minor triad with diminished seventh or half-diminished seventh chord; their names may seem daunting but you can easily memorize them by remembering their formula: 1 3 5 b7