Altered Chords

Congratulations on mastering triads, seventh chords, ninth chords, eleventh chords, and thirteenth chords. Now, we’ll learn how to modify these chords for different musical contexts.

Introduction to Altered Chords

Any chord—major, minor, augmented, or dominant—can be altered to change its character or "color." For example, dominant seventh chords (root, major third, minor seventh) can have their 5th, 9th, 11th, or 13th tones altered. Raising or lowering these extensions by a half-step creates tension and enhances resolution when moving to a stable chord (e.g., the tonic).

Rules for Notation:

1. Start with the chord’s base quality (major, minor, dominant).
2. Add alterations in parentheses. For multiple alterations, list higher extensions first.
   • Flat = ♭ or -
   • Sharp = ♯ or +

Examples:

• C11: C major ninth chord with a 11th (C + E + G + B♭ + D + F).
• C9(+11): C major ninth chord with a raised 11th (C + E + G + B♭ + D + F♯).

• C#9 ( #11): C major ninth chord with a raised 9th and 11th (C + E + G + B♭ + D# + F♯).

• C7(♭9♭5): C dominant seventh chord with flatted 9th and 5th (C + E + G♭ + B♭ + D♭).

Using Altered Chords in Progressions

The ii ➔ V ➔ I Progression

The main purpose of modifying chords is to increase the effect of the progression. In previous lessons, we have learned how to use the dominant seventh chord more effectively than the dominant triad in "2 ➔ 5 ➔ 1" and other chord progressions. The following chart shows different combinations of modified chords.

Altered chords add dramatic tension to common progressions. Compare these variations:

• Basic:
  Dm7 ➔ G7 ➔ Cmaj7

• With Altered Dominants:
  D7(♯9) ➔ G7(♯9♯5) ➔ Cmin9

The iii ➔ vi ➔ ii ➔ V ➔ I Progression

Modify chords to create jazzier textures:

• Original:
  E7 ➔ A7 ➔ D7 ➔ G7 ➔ Cmaj7
• Altered Version:
  Eø (Emin7♭5) ➔ A7(♭9) ➔ Dmin9 ➔ G13 ➔ Cmaj9

Extended Progression: vii° ➔ iii ➔ vi ➔ ii ➔ V ➔ I

Experiment with advanced alterations:

• Original:
  Bdim ➔ Emaj ➔ Amin ➔ Dmin ➔ G7 ➔ Cmaj
• Altered Version:
  Bmin11 ➔ E13(♭9) ➔ Amin9 ➔ Dø (Dmin7♭5) ➔ Cmaj/G ➔ G13 ➔ G9(add13) ➔ Cmaj

Purpose of Alterations

• Tension & Release: Altered chords (e.g., ♭9, ♯11) create dissonance that resolves satisfyingly to stable chords.
• Voice Leading: Smooth transitions between altered extensions (e.g., ♭9 ➔ 5th of the tonic).
• Stylistic Flexibility: Essential for jazz, blues, and gospel harmony.

Example Walking Bassline for G13:

Left hand: **G → B → D → E → F → E → D → B → G**  

Key Takeaways

1. Notation Matters: Always specify alterations clearly (e.g., G7(♯9♯5)).
2. Contextual Use: Apply alterations where resolution feels natural (e.g., dominant ➔ tonic).
3. Simplify When Needed: Omit non-essential tones (e.g., omit the 11th in a G9(add13)).

Final Exercise:
Reharmonises a blues progression using altered dominants (e.g., replace G7 with G7(♭9♯11)) and observe the heightened emotional impact.

Master these techniques, and you’ll unlock infinite harmonic possibilities! 🎶