Root Position and First Inversion Triads

Like intervals, triads can be inverted by moving the lowest note up an octave.

The lowest note of a triad, called the bass note, determines the name of the inversion. When the lowest note of a triad is the root of the chord, the triad is in root position. The example above is a triad in root position. The best way to recognize a chord's root is to rearrange the chords in thirds. Once that is accomplished, the note that the chord is built upon is the root. For example the notes CAE can be rearranged and spelled in thirds as ACE. Since "A" is the note that the triad is built upon, it is considered the root of the chord.

Next, let's invert the chord. The bass note is now the third of the chord. This is called first inversion. First inversion chords occur often in music. Any time a triad (chord) has the third of the chord in the bass, the chord is said to be in first inversion. The root of the chord is now a 6^th above the bass because of the inverting process. In the first inversion of the C-major triad shown here, the bass is E—the third of the triad—with the fifth and the root stacked above it (the root now shifted an octave higher), forming the intervals of a third and a sixth above the inverted bass of E, respectively.

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