Standard 6: Seventh Chords

Our objectives:

  • Identify all seventh chords, including: major seventh, minor seventh, dominant seventh, diminished seventh, and half-diminished seventh
  • Identify the root and quality of a seventh chord by using a lead sheet symbol
  • Complete a seventh chord with a given root and quality

6.1 What is a "seventh chord"?

We conclude our study of the fundamentals of music theory with one more type of chord - one that includes four notes sounded together.

A Seventh Chord is a four-note chord whose pitches can be arranged as thirds. Like with a triad, the pitches belonging to a seventh chord occupy adjacent positions (a four-pitch-class clump) on the circle of thirds.

Also like a triad, we attribute names to each member of the chord. The four members of a seventh chord are named as: the root, third, fifth, and seventh.

A seventh chord (A, C, E, G) on the diatonic circle of thirds.

6.2 Types of Seventh Chords

There are five qualities of seventh chords that appear in diatonic music: major seventh, dominant seventh, minor seventh, diminished seventh (also called fully-diminished), and half-diminished seventh. They are comprised of the following intervals above their roots:

  • major seventh: Major 3rd, Perfect 5th, and Major 7th above the root (or major triad with a major seventh)
  • dominant seventh: Major 3rd, Perfect 5th, and Minor 7th above the root (or major triad with a minor seventh)
  • minor seventh: Minor 3rd, Perfect 5th, Minor 7th above the root (or minor triad with a minor seventh)
  • diminished seventh: Minor 3rd, Diminished 5th, and Diminished 7th above the root (or diminished triad with a diminished seventh)
  • half-diminished seventh: Minor3, Diminished 5th, and Minor 7th above the root (or diminished triad with a minor seventh)

Try your hand at identifying the quality of different seventh chords.

Here's another exercise where you will construct a given seventh chord quality. Note that all the notes have already been arranged for you in thirds. You'll need to add the correct accidentals by using the controls below the staff.

Take a listen at the five different types of seventh chords below. They are presented in order: C major seventh, C dominant seventh, C minor seventh, C diminished seventh, and C half-diminished seventh:

6.3 Lead Sheet Symbols for Seventh Chords

The following are the lead-sheet abbreviations for the different types of seventh chords:

  • major seventh: maj7 or △7 (Gmaj7 or G△7)
  • dominant seventh: 7 (B7)
  • minor seventh: m7 (F♯m7)
  • diminished seventh: dim7 or °7 (Ddim7 or D°7)
  • half-diminished seventh: ⦰7 (A⦰7)

6.4 Conclusions: What's next?

Now that you have completed the six standards in the Fundamentals of Music Theory part of this textbook, you are ready to continue exploring the more advanced topics in music theory, including different types of minor scales (and other scales as well), how to create chord progressions by understanding the principles of harmony, species counterpoint, four-part texture, non-chord tones, and chromaticism.

Take a look at Open Music Theory for more information and exercises about these topics - and more!