Augmented Sixth Chords: A Journey of Tension and Resolution 🎵

Introduction

Get ready to add a touch of drama and emotion to your music! 🎹 Augmented sixth chords are one of the most fascinating and powerful harmonic tools in music theory. They’re not just chords; they’re true tension catalysts that guide us toward satisfying resolution moments, creating unforgettable transitions and modulations. Their distinctive sound, with that characteristic augmented sixth interval, has been used by composers from the Baroque to contemporary music to evoke profound emotions. In this article, we’ll break down the three main types: the Italian, the French, and the German, so you can master them and enrich your own compositions. Let’s explore this magical corner of harmony! 🚀

Main Concept

At the heart of augmented sixth chords lies a key interval: the augmented sixth. This interval is typically formed between the bVI (flat sixth degree) and the #IV (sharp fourth degree) of the key they’re heading toward. Both degrees have a strong tendency to resolve by semitone to the notes of the V (dominant) chord of the target key, generating a sense of anticipation and movement.

These chords don’t have a traditional functional “root” like diatonic chords; rather, their identity is defined by the presence of this augmented sixth interval and their characteristic resolution. Generally, they’re built on the bVI of the key they’re going to resolve to, and their main function is to prepare the V chord or, occasionally, directly the I.

There are three main types, differentiated by the intermediate notes that accompany the augmented sixth:

• Italian Augmented Sixth Chord (It+6): The simplest of the three, composed of three notes.
• French Augmented Sixth Chord (Fr+6): Adds one more note, creating a richer and more dissonant sonority.
• German Augmented Sixth Chord (Ger+6): Also four notes, but with a structure that allows for interesting harmonic ambiguity.

To better understand their differences, let’s look at their construction in relation to the tonic (I) of the key they resolve to (using C major as an example of target key, where the bVI is Ab and the #IV is F#):

💡 Key observation: Notice how all three types share the core augmented sixth interval and the [bVI]-[I] framework, but each adds different color notes that create unique tension and resolution qualities!

Examples

Let’s see these chords in action with practical musical contexts:

Example 1: Modulation from C Major to E Minor 🎭

A classic use of augmented sixth chords is to facilitate smooth modulations. Here’s how a German sixth chord helps us move from C major to E minor:

• Chord progression: IV (F major) → Ger+6 (Ab-C-Eb-F#) → V (B7) → i (E minor)
• What happens: The German sixth on Ab creates strong tension that pulls toward the dominant of the new key (B7), making the modulation feel natural and inevitable.
• Resolution path: The #IV (F#) resolves upward to G, while the bVI (Ab) resolves downward to G, both landing on the V chord.

Example 2: The Italian Sixth in a Cadential Context 🎼

The Italian sixth works beautifully as a pre-dominant preparation, similar to how IV or ii chords function:

• Chord progression: IV (F major) → It+6 (Ab-C-F#) → V (G7) → I (C major)
• Why it works: The Italian sixth creates more tension than a regular IV chord, making the arrival on V feel more dramatic and satisfying.
• Voice leading: Ab moves to G, C moves to B (the leading tone of V), and F# moves to G, creating that signature outward resolution pattern.

Example 3: The French Sixth for a More Colorful Approach 🌈

When you want extra color and dissonance, the French sixth is your go-to choice:

• Chord progression: vi (Am) → Fr+6 (Ab-C-D-F#) → V (G7) → I (C major)
• Special feature: The added D note (the IV degree) creates an augmented fourth or tritone interval with the bass, adding even more tension and color to the progression.
• Effect: This creates a rich, complex sound that resolves beautifully to the dominant chord, perfect for more expressive moments.

Practical Summary

Here are the key takeaways to help you master augmented sixth chords:

✅ Core Principles to Remember:

• Defining interval: All augmented sixth chords feature the augmented sixth between bVI and #IV
• Primary function: They serve as predominant chords, preparing the V or leading directly to I
• Resolution pattern: The outer voices resolve outward in contrary motion to the dominant chord
• Three main types: Italian (3 notes), French (4 notes with IV), German (4 notes with bII)

🎯 How to Use Them Effectively:

1. Identify your target key and determine where you want to arrive (usually V or I)
2. Choose your chord type based on the level of tension and color you want:
   • Italian: For clean, direct resolution
   • French: For maximum dissonance and color
   • German: For rich, complex harmonies with ambiguity
3. Construct the chord on the bVI of your target key
4. Voice lead properly - maintain the outward resolution of the augmented sixth interval
5. Use strategically for modulations, cadential preparations, or dramatic moments

🎹 Quick Reference Table:

Practice incorporating these chords into your compositions, and you’ll soon discover why they’ve been a favorite of composers like Bach, Beethoven, and Chopin! 💡 Remember: the magic of augmented sixth chords lies in their ability to create tension that demands resolution - use this power wisely to enhance your harmonic storytelling! 🚀