Chord inversion


Audio: chord inversion (0:08)

Chord inversion
Figure: chord inversion

chord inversion plays chord inversions in the key of C on an electric piano. The chord inversion figure shows the score. The first chord in root position and the rest in first or second inversion. The chords are notated in slash chord notation above the score and Roman numeral notation below. The chord progression is exactly the same as that in triad.

Chord inversion determines which is the lowest pitched note in a chord.

The lowest pitched note, the bass note, can be any of the notes in a chord:

  1. Root position: the bass note is the root. A root position chord is not inverted.
  2. First inversion: the bass note is the third above the root.
  3. Second inversion: the bass note is the fifth above the root.

An inverted chord is notated in Roman numeral notation by adding a lower case letter after the number:

  • a: root position (in practice, the trailing a is usually omitted).
  • b: first inversion.
  • c: second inversion.

There are other ways to notate an inverted chord:

  • Slash chord notation is in the form: chordname/rootnote, with the chord name preceding the root note. The slash chord, C/E, in bar 4 of chord inversion is a first inversion C major chord with note E in the bass.
  • Figured bass notation is written as two numbers one on top of the other. They indicate the intervals to be played above the lowest pitched note in the chord.

The order of the notes above the bass note is immaterial. In a C major chord, for example, CEG and CGE are both root position chords; EGC and ECG are first inversion chords; and GCE and GEC are second inversion chords.

Any note in a chord can be doubled. The sound of the chord changes but the quality of the chord remains unchanged. For example, the F major chord in bar 2 of chord inversion contains the four notes, CFAC. The chord is an F major triad, FAC, with a doubled C note. Since the bass note is note C, which is a fifth above the root F, the chord is in second inversion and notated F/C or IVc.

Chord inversion applies only to a triad. Strictly speaking, this chapter should be titled triad inversion, although chord inversion is a more commonly used term. There is one exception, a seventh chord, which is a four note tertian chord constructed from thirds, and can be in root position, first inversion, second inversion and, also, third inversion.

Chord inversion does not change the nature of a triad but it has a marked effect on the sound.