Seventh chords provide musicians looking to expand their harmonic vocabulary a way forward, shaping the mood and texture of piano music across most genres.
A seventh chord consists of three notes from a triad joined together with an interval of seven notes added – making them inherently dissonant and needing to be handled carefully to achieve sound.
Root
When faced with a chord symbol containing up to seven notes, it may seem dauntingly complex. One helpful way of thinking about this issue is that seventh chords add an interval above third note, meaning their roots correspond with first, fourth and fifth notes of major triad.
Seventh chords can also be categorized based on how they behave musically, for instance the ii6/5 and dominant seventh chords fall under this category as they perform certain musical tasks.
A seventh chord’s quality is determined by its triad and seventh. Chords constructed on me and le (3(1) and 2)(2) contain major triads with major sevenths; those constructed using sol and re (5(1) and 7)(5) contain minor triads with minor sevenths. Diminished triads create subdued qualities: those constructed using te and fa (1(1) and 5)(5) have half-diminished sevenths while ti and fe (7(1) and 7)(5) contain fully diminished sevenths.
Third
A seventh chord adds one note a third higher than its fifth note to create a dissonant sound and should not be used in major key signatures. Furthermore, adding this sixth note destabilizes and can create tension within any progression.
Sevenths can be broken down into several different categories based on their quality: major, minor, diminished and half-diminished. Each type has a distinctive sound and function in music.
As it can be difficult to distinguish these qualities simply from looking at a triad, to get an understanding of each seventh chord it may help to see it on a staff. Simply draw its root note onto it and write notes which represent its third, fifth and seventh degrees above it (in other words draw an extra-long snowman).
A chord’s quality can be determined by its combination of triad type and seventh type, such as major or minor seventh chord. Major seventh chords consist of major triads with major sevenths while minor sevenths feature minor triads and minor sevenths as their building blocks.
Fifth
A seventh chord contains four notes – its root, third, fifth, and an additional note with dissonant qualities – plus an added dissonant note that creates dissonance. Although dissonant sounds may not always sound appealing in tonal music, seventh chords remain extremely prevalent and can convey anything from comforting warmth to nervous tension.
To identify the quality of a seventh chord, it can help to assess its stack of notes on the staff. When stacked closely together, triad notes are called bottom, second, and head respectively.
When a seventh chord contains both a major triad and major seventh, it is known as a “maj7” chord. Minor sevenths and diminished sevenths can also be found within diminished triads – half-diminished sevenths adding another minor seventh while fully diminshed sevenths simply double the diminished chords.
Seventh
Seventh chords provide richer textures than their triad counterparts. They can add dissonance and depth to a tonal landscape, as well as being used to convey emotions or tell stories through music.
Just like triads, seventh chords can be constructed in any scale degree. Certain seventh chords containing an arpeggiated leading tone may be considered dominant or subdominant chords and will behave predictably when used within musical context.
Other seventh chords are known as chordal or non-tertian sevenths. They’re formed using chords below them and usually resolve through falling-fifth root motion.
There are five qualities of seventh chords: major, minor, diminished and augmented. Each quality gives seventh chords their unique colors: warm tension or soulfulness depending on its quality. Understanding them lies within their interval relationships between notes; let’s examine a C minor 7th chord for instance as an example.