Seventh chords add depth and variety to piano music by offering richer harmonies than their triad counterparts. Seventh chords can be constructed on any scale degree and, by definition, contain dissonant seventh notes.
This lesson will examine various kinds of seventh chords found in minor keys, and explore their qualities.
Major 7th
This 7th chord is one of the most frequently used 7th chords, especially in blues music. It boasts an appealing, pleasant tone and is simple to play.
The distance between the third and seventh tones of a chord determines its quality; when this distance is wide enough, dissonance increases drastically.
To transform this chord into major, raise its third by half-step to C and E (also known as lowering its fifth). This provides for a more secure sound.
Notation for this chord may appear intimidating, but it’s actually easy to grasp. The first note in this chord is a major triad with a minor seventh (hence its name); its second note, however, is an altered diminished seventh – giving this sound its distinct sound and making this chord popular among James Bond movies due to its use therein. Additionally, its use makes this an excellent way of practicing improvising, as there’s much room for variation within it.
Minor 7th
Seventh chords, like triads, are four note chords that can be stacked vertically so their notes fall on adjacent lines or spaces of the staff. When assembled this way, they resemble an extra-long snowman with its bottom, two middles, and head arranged like this. Because seventh chords are inherently dissonant they’re used to add emotion and texture to musical harmony.
To assess a seventh chord’s quality, we study its third, fifth and seventh intervals along with its root triad’s root note. These intervals tell us which kind of seventh chord it is.
Harmonic minor keys offer their own diminuendo triad based on vii, unlike major keys which require us to alter one chord tone to form one. When prepared like its V7 counterpart, this diminuendo 7 can resolve by falling-fifth root motion to produce sonorities with roots one fifth lower.
Dominant 7th
Dominant seventh chords have the power to create tension and urgency, making them popular as fifth chords in 2-5-1 progressions due to their close affinity with their tonic chord (C).
A dominant seventh chord is composed of three major triads and an altered seventh, eliminating any tritone notes to make for a much more stable-sounding chord.
To create a dominant 7th chord, start from the root note and work your way up through each scale degree until reaching the seventh note. From there, use this note interval table to find its distance from its respective root note.
Use letter notation to identify chords; for instance, VII could mean G dominant seventh chord in 1st inversion or VIIb could mean C minor scale chord in 3rd inversion. You could also use the formula 1-3-5-7-9 instead if letter notation is difficult for you – this method also works well when dealing with chords similar to dominant sevenths such as 9th chords.
Half-Diminished 7th
A diminished seventh chord can be one of the more challenging chords to learn because it requires you to lower every other note by half steps. While you can manually follow steps for either major or minor seventh chords, mastering this method takes much longer and will ultimately make playing these chords much simpler.
Half-diminished seventh chords share the same interval with diminished triads (m7b5), and thus feature a minor seventh of b5. However, their seventh is flattened out by one semitone and becomes unstable as a result.
Consequently, it’s less stable than either major or minor seventh chords, yet still more secure than an augmented or diminished seventh. Due to its flattened seventh note, however, this chord should usually only be used as an accessory chord rather than as a whole chord itself; due to its potentially unstable and dissonant tone it’s best used between other chords; although knowing about this chord could prove useful!