Unit 3: Harmony Fundamentals - Triads and Seventh Chords

Triad

A three-note chord consisting of a Root, a Third, and a Fifth.

Root

The fundamental note upon which a chord is built.

Third

The note interval of a third above the root, determining if the chord is Major or Minor.

Fifth

The note interval of a fifth above the root, determining if the chord is Augmented or Diminished.

Major Triad

A triad with a Major 3rd and Perfect 5th from the root.

Minor Triad

A triad with a Minor 3rd and Perfect 5th from the root.

Diminished Triad

A triad consisting of two Minor 3rds and a Diminished 5th from the root.

Augmented Triad

A triad with two Major 3rds and an Augmented 5th from the root.

Symbol for Major Triad

Uppercase Roman Numeral or Capital Letter (e.g., I, V or C).

Symbol for Minor Triad

Lowercase Roman Numeral or Letter + 'm' (e.g., ii, vi or Cm).

Symbol for Diminished Triad

Lowercase Roman Numeral with degree symbol or Letter + 'dim' (e.g., vii$^
atural$, Cdim).

Symbol for Augmented Triad

Uppercase Roman Numeral with plus sign or Letter + 'aug' (e.g., III$^+$, Caug).

Major Seventh Chord

A triad with a Major 7th added to a Major triad.

Major-Minor Seventh Chord

A Major triad with a Minor 7th, also known as Dominant Seventh.

Minor Seventh Chord

A Minor triad with a Minor 7th added.

Half-Diminished Seventh Chord

A Diminished triad with a Minor 7th added.

Fully-Diminished Seventh Chord

A Diminished triad with a Diminished 7th added.

Diatonic Chords

Chords built using only the notes of a specific key and scale.

Inversions

Different arrangements of the notes in a chord based on which member is in the bass.

Root Position

When the root of the chord is the lowest note.

First Inversion

When the third of the chord is in the bass.

Second Inversion

When the fifth of the chord is in the bass.

Major Key Diatonic Pattern

I, ii, iii, IV, V, vi, vii$^
atural$.

Natural Minor Key Pattern

i, III, iv, VI, VII.

Harmonic Minor Key Pattern

V (Major), vii$^
atural$ (Diminished).

Imperfect 5th

A fifth found in Major and Minor triads.

Altered 5th

A fifth that is lowered or raised, found in Diminished and Augmented triads.

Figured Bass

A system of notation that indicates the intervals above the bass note.

Figured Bass for Root Position

Represented by 5/3 or left blank.

Figured Bass for First Inversion

Indicated as 6 (short for 6/3).

Figured Bass for Second Inversion

Indicated as 6/4.

Floating Accidental

An accidental under a bass note that applies to the third above the bass.

Slashed Notation in Figured Bass

Indicates that the note related to that interval should be raised by a half step.

Common Mistake: Half vs. Fully Diminished

Confusing vii$^
atural 7$ in Major keys (Half-Diminished) with Fully Diminished in Minor keys.

Common Mistake: Figured Bass Counting

Thinking figured bass numbers count from the root rather than the bass note.

Common Mistake: Inversion Counting

Mixing up 2nd inversion ($6/4$) with 1st inversion ($6$).

Common Mistake: Floating Accidental

Assuming an accidental under the staff applies to the bass note.

Diatonic Seventh Chords

The seventh chords formed based on the triads of their respective key.

Leading Tone Chord

The vii$^
atural$ (Diminished) chord acting as a dominant function chord.

Subtonic Chord

The VII (Major triad on lowered 7th scale degree) in Natural Minor.

Major Seventh Chord Symbol

Symbolized as I$^7$ or Cmaj7.

Dominant Seventh Chord Symbol

Symbolized as V$^7$ or C7.

Minor Seventh Chord Symbol

Symbolized as ii$^7$ or Cm7.

Half-Diminished Seventh Chord Symbol

Symbolized as vii$^
atural 7$ (in Major) or ii$^
atural 7$ (in Minor).

Fully-Diminished Seventh Chord Symbol

Symbolized as vii$^
atural 7$ (in Harmonic Minor).

Imperfect 5th Definition

Found in Major and Minor triads.

Altered 5th Definition

Found in Diminished and Augmented triads.