Week 10 of 16

Diminished & Augmented Chords

Beyond major and minor, there are two more triad types: diminished and augmented. This week completes your knowledge of the four basic chord qualities.

Learning Goals

Build diminished triads (Root + m3 + dim5)
Build augmented triads (Root + M3 + aug5)
Hear and name all four triad types
Understand where diminished and augmented chords appear in scales

Lesson Content

Diminished Triads

A diminished triad = Root + Minor 3rd (3 half steps) + Diminished 5th (6 half steps from root). Both intervals are "squeezed" smaller. The result is a tense, unstable chord that wants to resolve.

  • B Diminished: B - D - F
  • In C major, the triad built on the 7th degree (B) is naturally diminished

Augmented Triads

An augmented triad = Root + Major 3rd (4 half steps) + Augmented 5th (8 half steps from root). Both intervals are "stretched" wider. Augmented chords sound dreamy, floating, and unresolved.

  • C Augmented: C - E - G#
  • Augmented triads appear naturally in harmonic minor on the 3rd degree

Comparing All Four Triads (from C)

  • C Major: C - E - G (bright, happy)
  • C Minor: C - Eb - G (dark, sad)
  • C Diminished: C - Eb - Gb (tense, scary)
  • C Augmented: C - E - G# (dreamy, floating)

Practice Activities

Activity 1: Play All Four Triad Types

On the Synthesizer, play each type from C: C-E-G (major), C-Eb-G (minor), C-Eb-Gb (diminished), C-E-G# (augmented). Repeat from other roots like D and G.

Activity 2: Chord Identification — Intermediate

Move to Intermediate difficulty in the Chord Identification game. This adds diminished and augmented chords. Use both Block and Arpeggio play styles.

  • Diminished sounds "crunchy" and tense
  • Augmented sounds "spacey" and open
  • Aim for 60%+ accuracy with all four types

Activity 3: Note Reading — More Keys

Push your note reading to keys with 2-3 sharps or flats (D Major, Bb Major, Eb Major). Try Intermediate difficulty for a wider note range.

Activity 4: Chord Reading — Intermediate

Move to Intermediate difficulty in the Chord Reading game. Now you will read diminished and augmented chords on the staff alongside major and minor. Watch for the altered notes that define each quality.