Overview
This lecture explores the augmented triad, its construction, sound characteristics, use in chord progressions, and its unique qualities in music composition and modulation.
Augmented Triad Basics
- An augmented triad consists of a root, a major third (4 half steps up), and an augmented fifth (another 4 half steps).
- Example: C augmented = C, E, G#.
- The chord sounds ambiguous and creates a sense of uneasiness or tension.
Emotional and Compositional Uses
- Augmented chords evoke discomfort or mystery, making them useful for sci-fi, spooky, or ambiguous moods.
- They can be isolated for dramatic effect or used to create unusual emotional atmospheres.
Augmented Chords in Progressions
- Every major key has seven diatonic chords, with the dominant (V) being the fifth chord.
- The V chord can be replaced with an augmented chord for more color and tension in resolving to the tonic (I).
- Example: In A major, E augmented (E, G#, C) can replace E or E7 as a dominant chord.
Extensions and Variations
- Adding a flat seventh to an augmented triad creates an augmented seventh chord (e.g., E7#5).
- Adding a major seventh creates a more dissonant chord but can still resolve to the tonic.
- These extensions intensify the chord's tension before resolution.
Voice Leading and Modulation
- Augmenting the fifth of a chord (raising it by a half step) creates smooth voice leading toward chords containing the new note.
- Augmented chords can bridge between I and vi, IV, or ii chords in a major key.
- Only four unique augmented triads exist due to the chord's symmetry (the inversion is determined by bass note).
Augmented Chords for Modulation
- Using each of the four augmented triads can facilitate modulation to new keys.
- Augmented chords can serve as dominant or secondary dominant chords in progressions for key changes.
Augmented Chords and Tonality
- Entire tonalities can center on augmented chords, using modes like the melodic minor scale to create ambiguous, cinematic sounds.
- Centering a scale around the augmented triad produces an indistinct, unsettling tonality, useful for film music.
Relationship to Minor Major Seventh Chords
- Any augmented triad becomes a minor major seventh chord by placing a note a half step above any triad note in the bass.
- Example: A augmented (A, C#, F) + F# in the bass = F# minor major seventh.
Key Terms & Definitions
- Augmented Triad — A chord made of a root, major third, and augmented fifth (two stacked major thirds).
- Voice Leading — The smooth movement of individual notes between chords.
- Dominant (V) Chord — The fifth chord in a key, typically resolves to the tonic (I).
- Augmented Seventh Chord — An augmented triad with an added flattened seventh (e.g., E7#5).
- Minor Major Seventh Chord — A minor triad with an added major seventh interval.
Action Items / Next Steps
- Experiment with augmented chords as substitute dominants and in modulations.
- Try composing a progression using all four augmented triads.
- Explore melodic minor modes centered on augmented chords for cinematic effects.