Topic 12: Exploring Beyond Triads - Unveiling Seventh Chords

 

The exploration of chords extends beyond the simplicity of triads. Seventh chords add a new layer of complexity and richness to our harmonic vocabulary. As we journey through the harmonization of the C major scale, let's delve into the world of seventh chords.

Deriving Seventh Chords on the C Major Scale: Elevating Harmonic Complexity

Building upon the triads we crafted from the C major scale, let's augment our harmonic landscape by introducing seventh chords. These chords, consisting of four notes, bring a heightened sense of depth and sophistication to our musical palette.

How to build a seventh chord

We have seen that triads, major triads were created by the concatenation of two triads. Sevenths in some way continue this rule by adding another third to the fifth of the chord. Depending on these thirds, we will have different types of seventh chords.

There are five types of seventh chords that are commonly used in music. Each type has its own characteristic sound. Let's take a closer look at each type.

 

Dominant Seventh Chord

One noteworthy seventh chord is the dominant seventh chord. To comprehend this chord's significance, we must first understand its role in creating tension and resolution within a musical context. The dominant seventh chord is characterized by the root, major third, perfect fifth, and minor seventh (10 semitones). For example, a C dominant seventh chord contains the notes C, E, G, and Bb. (Bb is a minor seventh/10 semitones above C).

Major seventh chord

Compared to the dominant seventh chord, the major seventh chord sounds much softer. It is made by raising the root of a major triad by a major seventh (11 semitones). For instance, the sounds C, E, G, and B make up a major seventh chord in C (B is a major seventh that is located 11 semitones above C).

Minor seven chord

Minor seventh chords are created by combining a minor triad with a minor seventh (10 semitones above the root). For instance, a C minor seventh chord consists of C, Eb, G, and Bb — where Bb is the minor seventh (10 semitones higher than C).

Half-dismished seven chord

The half-diminished seventh chord is created by taking a diminished triad and a minor seventh (10 semitones) above the root. For example, a half-diminished seventh chord in C contains the notes C, Eb, Gb, and Bb.

Dismished seven chord

A diminished seventh chord is a type of seventh chord that is built by taking a diminished triad and adding a minor seventh above the root (9 semitones). A diminished triad is a triad that consists of three notes that are all a minor third apart. To build a diminished seventh chord, start with a diminished triad. For example, to build a diminished seventh chord in C, start with the root note C, add three semitones from C to find the third, Eb. add other three semitones from Eb to find the fifth, Gb. The notes of a diminished seventh chord in C are therefore C, Eb, Gb, and Bbb (A).

The Dominant Chord's Role: Setting the Stage for Resolution

The dominant seventh chord plays a pivotal role in establishing tension and guiding the listener's ear toward resolution. It often precedes the tonic chord, creating a sense of anticipation and leading to a satisfying resolution. In the key of C major, the G7 chord sets the stage for the resolution to the C major chord, creating a dynamic and compelling progression.

The dominant seventh chord emerges as a key player in shaping the emotional landscape of a musical piece. Its unique blend of tension and resolution adds a touch of drama and excitement, enriching the harmonic tapestry and offering musicians a powerful tool for crafting engaging and evocative compositions.