Understanding 7th Chords

Review

This lesson assumes you are already familiar with building and identifying triads.

To review Traids go to Understanding Triads and Triad Types.

Overview

1. Seventh chords are triads with one more 3rd stacked on top.
   Triad 7th Chord            𝄂
2. The top note when stacked in thirds is called the 7th of the chord.
3. Seventh chords are described by naming the triad type and then the 7th type (interval from the root to the 7th). So, a major triad with a major 7th (the interval of a major 7th between the root and the 7th) is a major-major 7th chord.
   Major Major-Major            𝄂
4. In reality, only 5 types of 7th chords are used in most music. By convention, each of the five types of 7th chords have shorter names. The standard shorthand is listed in parentheses after the name.
• Major-Major 7th chord = Major 7 chord (M7). Since both the triad and 7th are major it is usually called a Major 7 chord.
  M7        𝄂
• Major-minor 7th chord = Dominant 7 chord (Mm7). The name "Dominant" comes from the fact that it only occurs naturally when built on a dominant (scale degree 5) root.
  Mm7         𝄂
• minor-minor 7th chord = Minor 7 chord (m7). Since both the triad and 7th are minor it is usually called a Major 7 chord.
  m7          𝄂
• diminished-minor 7th chord = Half-diminished 7 chord (^Ø7). It is called half-diminished because the 7th is not diminished.
  ^Ø7           𝄂
• diminished-diminished 7th chord = Diminished 7 or Fully-diminished 7 chord (^o7)
  ^o7           𝄂

Identifying 7th Chords

1. Identify the triad. The bottom three notes make up a B minor triad.
         𝄂
2. Identify the seventh. The interval between the root and the 7th is a minor 7th.
       𝄂
3. The type of 7th chord is the combination of the two. The combination of the two gives us a B minor-minor 7th chord. "Minor-minor" is normally simplified to "minor". Therefore, this is a B minor 7th chord.

Building 7th Chords

1. Build the triad. A Half-Diminished 7 chord is a diminished triad with a minor 7th. Therefore, the triad is a G diminished chord.
          𝄂
2. Add the seventh. A Half-Diminished 7 chord has a minor 7th between the root and the 7th. Therefore we need to add an F natural to complete the 7th chord.
           𝄂

Next Exercises

In the next two exercises you will identify and then build 7th chords in root position, stacked in close position, like the examples above. We will use the common names (those in blue) for these exercises. In other words, a D Dominant 7 is a D major-minor 7 chord.