NCVPS AP Music TheoryCreated by Dr. Tom Moncrief

What is a Seventh Chord?

Tertian HarmonyTertian Harmony is creating tonal harmony by

stacking 3rds on top of each other. The Seventh Chord is a four-note chord consisting of a Root, a 3rd, a 5th and a 7th.

This is a Seventh chord based on the note “A”. The Root to the 3rd is (“A” to “C#”), the 3rd to 5th is (“C#” to “E”), and the 5th to 7th is (“E” to “G”).

Major Seventh ChordA Major Seventh Chord consists of a Major Triad

on the bottom and a Major 7th above the Root. The Major Triad is identified by a Major 3rd between the Root and 3rd and a minor 3rd between the Root and 5th.

In this Bb Major Seventh Chord, there is a Major 3rd from Root to 3rd (“Bb” to “D”), a minor 3rd from 3rd to 5th (“D” to “F”) and a Major 3rd from 5th to 7th (“F” to “A”).

Major-minor Seventh ChordA Major-minor Seventh Chord consists of a

Major Triad on the bottom and a minor 7th above the Root. The Major-minor Seventh Chord is commonly called the Dominant 7th because this is the quality of 7th chord that is built upon the dominant scale degree in a Major Key. The Major Triad is identified by a Major 3rd between the Root and 3rd and a minor 3rd between the Root and 5th.

Major-minor Seventh ChordThis is the C Dominant 7th chord. “C” is the

Dominant in the Key of F Major, this is why this chord has a “Bb” as “Bb” is in the Key Signature of F Major.

In this C Major-minor Seventh Chord, there is a Major 3rd from Root to 3rd (“C” to “E”), a minor 3rd from 3rd to 5th (“E” to “G”) and a minor 3rd from 5th to 7th (“G” to “Bb”).

Minor Seventh ChordA minor Seventh Chord consists of a minor Triad

on the bottom and a minor 7th above the Root. The minor triad is identified by a minor 3rd between the Root and 3rd and a Major 3rd between the Root and 5th.

In this E minor Seventh Chord, there is a minor 3rd from Root to 3rd (“E” to “G”), a Major 3rd from 3rd to 5th (“G” to “B”) and a minor 3rd from 5th to 7th (“B” to “D”).

Half-diminished Seventh ChordA half-diminished Seventh Chord consists of a

diminished triad on the bottom and a minor 7th above the Root. The diminished triad is identified by a minor 3rd between the Root and 3rd and a minor 3rd between the Root and 5th.

In this A half-diminshed Seventh Chord, there is a minor 3rd from Root to 3rd (“A” to “C”), a minor 3rd from 3rd to 5th (“C” to “Eb”) and a Major 3rd from 5th to 7th (“Eb” to “G”).

Fully diminished Seventh ChordA diminished Seventh Chord consists of a

diminished triad on the bottom and a diminished 7th above the Root. The diminished triad is identified by a minor 3rd between the Root and 3rd and a minor 3rd between the Root and 5th.

In this D fully-diminshed Seventh Chord, there is a minor 3rd from Root to 3rd (“D” to “F”), a minor 3rd from 3rd to 5th (“F” to “Ab”) and a minor 3rd from 5th to 7th (“Ab” to “Cb”).

Let’s Practice!What is the Quality

of this Seventh chord?

The AnswerWhat is the Quality

of this Seventh chord?

This is a Dominant Seventh Chord (or Major-minor Seventh Chord). There is a Major triad on the bottom (E, G#, B) and a minor 7th on top (“E” to “D” is a minor 7th).

Let’s Practice!What is the Quality

of this Seventh chord?

The AnswerWhat is the Quality of

this Seventh chord?This is a Major Seventh

Chord. The quality of the triad is Major (D, F#, A) and the quality of the 7th is Major (“D” to “C#” is a Major 7th). With a Major Triad and a Major 7th, the quality is a Major Seventh.

Let’s Practice!What is the Quality

of this Seventh chord?

The Answer What is the Quality of this Seventh chord?

This is a F Dominant Seventh Chord (Major-minor seventh). The triad (F, A, C) is Major and the quality of the 7th is minor (“F” to “Eb” is a minor 7th). With a Major Triad on the bottom and a minor 7th this is a Major-minor Seventh Chord.

Let’s Practice!What is the Quality

of this Seventh chord?

The AnswerWhat is the Quality of

this Seventh chord?This is a minor seventh

chord. The quality of the triad (B, D, F#) is minor and from the Root to the 7th is a minor 7th (“B” to “A”) is a minor 7th. With a minor triad and a minor 7th this is a minor seventh chord.

Let’s Practice!What is the Quality

of this Seventh chord?

The AnswerWhat is the Quality of

this Seventh chord?This is a half-diminished

7th chord. The quality of the triad (C, Eb, Gb) is diminished and the quality of the 7th is minor (“C” to Bb” is a minor 7th). With a diminished triad and a minor 7th, the quality is a half-diminished 7th chord.

Let’s Practice!What is the Quality

of this Seventh chord?

The AnswerWhat is the Quality of

this Seventh chord?This is a minor seventh

chord. The quality of the triad is minor (Ab, Cb, Eb) and the quality of the 7th is minor. With a minor triad and a minor 7th, this is a minor seventh chord.

Let’s Practice!What is the Quality

of this Seventh chord?

The AnswerWhat is the Quality of

this Seventh chord?This is a fully-diminished

seventh chord. The quality of the triad is diminished (A, C, Eb) and the quality of the 7th is a diminished 7th (“A” to “Gb”). With a diminished triad and diminished 7th, this is a diminished seventh chord.