Using Non-Diatonic Chords to Spice Up Your Songs

A lot of today’s pop music is based on diatonic chord progressions that are somewhat harmonically bland because the focus is on the lyrics and melody.  There is no reason, however, in your songwriting, that you can’t employ one or more interesting chords that are outside the key, and it’s easy to find them.  Non-diatonic chord progressions are a crucial tool in expanding harmonic possibilities and adding tension, contrast, and surprise to music.

Understanding Diatonic vs. Non-Diatonic

Before diving into specific progressions, it’s essential to clarify what diatonic and non-diatonic mean in the context of music theory.

• Diatonic Chords are derived from the notes within a specific key. In the key of C major, for example, the diatonic chords are C, Dm, Em, F, G, Am, and B diminished. These are built strictly from the notes of the C major scale (C, D, E, F, G, A, B).
• Non-Diatonic Chords involve at least one note outside of the scale. These chords don’t naturally belong to the key but are often used to add color, tension, or modulation to a song. Examples include borrowing from the parallel minor or major, chromatic shifts, and secondary dominants.

Borrowing Chords from Parallel Major and Minor

One of the most common ways non-diatonic chords are derived is through modal interchange or borrowing from parallel keys. For instance, if you’re writing in a major key, you can borrow chords from the parallel minor key (e.g., borrowing Fm and Ab when in C major). Similarly, in a minor key, you can borrow from the parallel major (e.g., borrowing C major in A minor).

• From Parallel Minor: Borrowing from parallel minor typically involves using chords like bIII, bVI, and bVII (e.g., borrowing Ab, Fm, and Bb from C minor while in C major).
• From Parallel Major: In a minor key, borrowing from the parallel major means you can incorporate I, IV, or V chords (e.g., borrowing A major or E major when in A minor).

Chromatic Chords and Tritone Substitutions

In addition to modal interchange, chromaticism and tritone substitutions play a big role in non-diatonic chord progressions.

• Chromaticism: A chromatic chord progression uses chords that are a half-step apart, creating a sense of tension. For example, moving from C to C#dim7 before resolving to Dm gives a unique chromatic sound.
• Tritone Substitution: In jazz, a tritone substitution involves replacing the dominant V chord with a chord a tritone away. For example, in the key of C major, you can replace G7 with Db7, adding a rich, unexpected flavor to the progression.

Common Non-Diatonic Progressions

Let’s now examine some of the most common non-diatonic chord progressions, with explanations on how they are derived and used.

 

B. Borrowing from Parallel Major

8. i – bVII – bVI – V7
   • Example: Key of A minor | Am | G | F | E7 |
   • Derivation: The V7 chord (E7) is often borrowed from A harmonic minor, where the 7th degree is raised to create a dominant chord with a strong resolution back to the tonic minor (Am). The raised 7th (G#) in E7 acts as the leading tone, pulling strongly toward the tonic, which is a hallmark of harmonic minor.
   • Application: This progression is frequently used in blues, jazz, and classical music. The inclusion of the V7 chord introduces a brighter, more complex sound to the minor progression, providing tension and an effective resolution.
9. i – IV – V – i
   • Example: Key of A minor | Am | D | E | Am |
   • Derivation: The IV (D) and V (E) chords are borrowed from A major, brightening the cadence and offering a stronger resolution than the diatonic minor alternatives, Dm and Em. These chords can also be viewed as derived from A melodic minor, where the 6th and 7th degrees are raised to mirror a major scale but with a flattened 3rd.
   • Application: This progression creates a dynamic cadence, often used in classical and traditional music to enhance the resolution of minor key passages by borrowing from the parallel major.
10. i – natural VIm – i – IVmaj

• Example: Key of D minor | Dm | Bm | Dm | G |
• Derivation: In this progression, the Bm chord is borrowed from D major, introducing a surprise element in a minor key progression. The G chord, also from D major, creates a Dorian-like quality when used without the Bm. The interaction between the minor tonic and borrowed major chords adds harmonic richness and interest.
• Application: This progression is famously used in the bridge of “I Heard It Through the Grapevine.” The contrast between the natural minor and borrowed major chords creates emotional depth and a unique harmonic flavor.

11. i – bVI – IV – VII – V

• Example: Key of E minor | Em | C | A | D | B |
• Derivation: Both the IV (A major) and V (B major) chords are borrowed from E major, while C remains from the minor scale. The chromatic voice leading from C to A to D to B creates a stepwise motion that adds tension and momentum before resolving to the tonic.
• Application: This progression is perfect for building tension, especially in ballads and progressive music. The chromaticism between chords enhances the harmonic pull, leading back to the tonic minor.

12. i – IV – bVII – V

• Example: Key of G minor | Gm | C | F | D |
• Derivation: The IV (C major) and V (D major) chords are borrowed from G major, while the presence of the bVII (F) retains the minor key flavor. The progression can be viewed as a combination of major and minor harmonies, with chromatic voice leading through C, F, and D to build toward resolution. The V major functions similarly to the V7 discussed in earlier examples, providing a strong dominant pull back to the tonic.
• Application: This progression is often heard in rock, classical, and folk genres. It provides a sense of forward motion and resolution through the combination of borrowed major chords with minor harmonies.

13. i – V – IV – i

• Example: Key of E minor | Em | B | A | Em |
• Derivation: Both the IV (A major) and V (B major) chords are borrowed from E major, adding a surprising brightness to the minor key progression. The IV–V–i resolution is familiar in classical and popular music, offering a satisfying conclusion to the progression.
• Application: This progression is commonly found in blues and rock. The use of major chords in a minor context creates harmonic contrast and interest, making the resolution to the tonic minor more impactful.

Non-diatonic chord progressions provide endless opportunities to experiment with harmonic variety, tension, and surprise. Whether you’re borrowing chords from parallel modes or using chromatic shifts, these progressions add depth to compositions across genres. Understanding how to use non-diatonic chords effectively will help you craft music that stands out, creating emotional moments that resonate with listeners.

By incorporating non-diatonic chords into your songwriting, you can transform even the simplest progressions into harmonically rich and engaging pieces.