🎵 Unit 3: Triads, Seventh Chords, and Harmonic Function

Triad

A three

Root

The fundamental pitch of a chord.

Third

The note a third above the root in a triad.

Fifth

The note a fifth above the root in a triad.

Major Triad

Built from a major third and perfect fifth above the root.

Minor Triad

Built from a minor third and perfect fifth above the root.

Diminished Triad

Built from a minor third and diminished fifth above the root.

Augmented Triad

Built from a major third and augmented fifth above the root.

Seventh Chord

A four

Major Seventh Chord

Major triad + major seventh.

Dominant Seventh Chord

Major triad + minor seventh.

Minor Seventh Chord

Minor triad + minor seventh.

Half

Diminished Seventh

Fully Diminished Seventh

Diminished triad + diminished seventh.

Roman Numeral Analysis

A way to label chords by scale degree and quality (I, ii, V7, etc.).

Tonic Function

Provides stability and rest in tonal harmony.

Dominant Function

Creates tension that resolves to the tonic.

Subdominant Function

Prepares the dominant and expands harmonic motion.

Inversion (of chords)

Changing which chord tone is in the bass.

Root Position

The root of the chord is in the bass.

First Inversion

The third of the chord is in the bass.

Second Inversion

The fifth of the chord is in the bass.

Figured Bass

A numerical shorthand indicating intervals above a bass note.

Cadence

A harmonic or melodic closure at the end of a phrase.

Authentic Cadence

V → I (strong final cadence).

Half Cadence

Ends on V (incomplete, unresolved).

Plagal Cadence

IV → I (“Amen” cadence).

Deceptive Cadence

V → vi (surprising, unresolved sound).

Voice Leading

The smooth movement of individual melodic lines between chords.

Parallel Motion

Two voices move in the same direction by the same interval.

Contrary Motion

Two voices move in opposite directions.

Oblique Motion

One voice stays the same while another moves.

Common Tone

A pitch shared by two successive chords.

Chord Progression

A sequence of chords that creates harmonic motion.