Major Seventh Chords and Inversions

Now it’s time to go beyond triads, into the world of four-part chords called seventh chords. When we add a fourth note to a triad, it is often the 7th of the chord, as the triad already contains the root, 3rd, and 5th. That is why four-part chords are sometimes referred to as “seventh” chords. The first four-part chord we will look at is the major seventh chord:

As with the triads in Chapter 10, the intervals from the root have been indicated (major 3rd, perfect 5th, and major 7th). These major and perfect intervals are found within the major scale, so you may think of this chord as the first, third, fifth, and seventh degrees of a C major scale.

The chord symbol above the staff is now Cmaj7. There are two components to this chord symbol: the root (C) and the suffix or description (maj7).

Like the triads, these four-part chords can also be inverted. Here are the inversions of a C major 7th chord:

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We’ll define these different inversions of the C major seventh chord as follows:

• the first chord is in root position (with the root on the bottom)
• the second chord is in first inversion (with the third on the bottom)
• the third chord is in second inversion (with the fifth on the bottom)
• the fourth chord is in third inversion (with the seventh on the bottom)
• the last chord is in root position, an octave higher than the first.

Next, we’ll go through the same process for some more commonly used four-part chords, starting with the minor 7th chord.

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We can also invert the C minor 7th chord, as follows:

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If we flat the 5th of the minor 7th chord, we get another useful chord, which is called… you guessed it… a minor 7♭5 chord:

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Note the new diminished 5th interval description on the previous page. When we take a perfect interval (such as a 5th) and reduce it by a half step, we get a diminished interval.

The “minor 7th ♭5” chord is also referred to as a half diminished or half diminished 7th chord.

We can invert the C minor 7th ♭5 chord, as follows:

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The last four-part chord we will look at in this section is the dominant 7th chord, which is built as follows:

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We do not use a specific symbol to indicate the word or function dominant. A chord symbol which consists of a note name followed only by the suffix 7 indicates a dominant 7th chord.

OK, you know what comes next… this dominant 7th chord can then be inverted, as follows:

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Play through all of these four-part chords (and their inversions) in the right hand, and then try playing them in the left hand (one octave lower). Then, try to become familiar with these chords built from all roots (i.e., D7, E7, F7, etc.).