Chord Extensions: Part I

Liverpool Music Lessons

Chord Extensions: Expanding Beyond the Triad

A chord extension is when additional notes are added to a basic chord to create a richer, more complex sound. These extra notes typically come from the scale and are added beyond the basic triad (root, third, and fifth) and seventh.

Common chord extensions include the 9th, 11th, and 13th, which provide extra layers of harmony. For example, in a Cmaj7 chord (C – E – G – B), adding a D (the 9th) creates a Cmaj9 chord, adding more depth to the original sound.

Chord extensions are used to add color and tension, making the chord progression more interesting.

 

  1. Defining the Triad
    • A triad consists of three core notes: the root, third, and fifth. For example, C major (C – E – G) or C minor(C – Eb – G) forms the base.
    • This triad provides the basic sound of the chord, but it lacks the full richness or complexity that extended harmonies offer.
  2. The 7th: The First Extension
    • The 7th is typically the first extension added to a chord, turning a triad into a 7th chord.
    • Even though the 7th is not “beyond the octave,” it’s considered an extension because it’s beyond the core triad.
    • Adding the 7th creates different types of chords (e.g., maj7, min7, and dominant 7) that add a layer of depth to the harmony.
  3. Extensions Beyond the 7th
    • Extensions beyond the 7th (like the 9th, 11th, and 13th) add more layers to the chord’s sound and begin to move “beyond the octave” of the root.
    • Each of these extensions introduces a new interval that changes the feel of the chord:
        • 9th: Adds brightness and space.
        • 11th: Softens the chord and adds a mystical quality.
        • 13th: Creates a lush, rich texture.

  4. Using Extensions Together
    • Extended chords often include more than one extension for a fuller sound. For example, a C13 chord could include the root, 3rd, 5th, 7th, 9th, and 13th.
    • These layered extensions produce harmonically rich chords frequently used in jazz and more complex harmonic progressions.

Quick Summary

  • Chord extensions start with the 7th, which, while technically within the octave, goes beyond the triad.
  • True “beyond the octave” extensions begin with the 9th, continuing to the 11th and 13th, adding increasing complexity and color.

Understanding this structure helps you recognize the role each note plays in expanding a basic triad into a richer, fuller chord!

 

Let’s read Part: II to learn more about chord extension rules.