9 Secondary Triads in First Inversion

Major

Minor

A. The ii⁶ chord

The ii⁶ chord prolongs the IV chord in major (ii^o6 prolongs the iv in minor). As with the IV chord, the ii⁶ chord has a doubled bass.

The ii⁶ chord is followed by the dominant or by the [ I ] – V⁽⁷⁾ formula. Contrary motion is employed to avoid parallel octaves (fa – so). The I – ii⁶ connection imitates the I – IV connection, with re replacing do of the IV chord. Works the same in minor.

Voice Leading using the ii⁶ chord

*Acceptable similar motion of all the voices of the I triad moving up to ii⁶ with the do – re or mi – fa soprano.

** In open spacing, unacceptable parallel P5^ths can occur between ii⁶ – [ I ].

Irregular doublings

As with I moving to IV, contrary motion is required when I moves to ii⁶ to avoid parallel octaves.

B. The vii^o6 chord

The vii^o6 chord with re in the bass substitutes the V  chord and the [ V ] chord (see Linear Six-Four Chords).

• The 3^rd (the bass) is doubled.
• The leading tone (ti) is never doubled and always moves to do. The other voices (re and fa) can move up or down.
• In harmonic minor, the leading tone is indicated as vii^o6 or vii^o6.

Voice leading using the vii^o6 chord

Major only to avoid le – ti A2.

**See “Other Uses of the Deceptive Resolution” in the chapter on Authentic, Half, Plagal, and Deceptive Cadences.

Voice leading considerations with the vii^o6 chord:

1a and 1b. The similar use of the vii^o6 and V  chords harmonizing the m – f – s soprano and d – r – m bass line. The d5 – P5 in the soprano and alto is acceptable as it is covered by the parallel 10^ths in the outer voices.

1b.  If the 5^th of the vii^o6 chord (fa) is in the soprano it is irregularly doubled an octave below.

2. The vii^o6 chord can also be used as a neighbor chord to a tonic chord with a m – f – s soprano. Parallel d5 to P5 are acceptable.

3. The m – f – m soprano ends on a I chord.

C. The iii⁶ and vi⁶ chords

The iii⁶ chord can substitute for the cadential [ I ] chord. In minor keys, the chord is an augmented triad in first inversion.

The vi⁶ chord often embellishes the tonic triad.

Voice leading using the iii⁶ and vi⁶ chords

Sample Progressions Employing Secondary Triads in First Inversion

*From melodic minor

Imperfect Circle of Fifths with Inversions

In minor keys, the cadence is always in harmonic minor (V – i ). The syllables below are in la-minor.