Secondary Triads in Root Position

Laszlo Cser; Daniel Wanner

7 Secondary Triads in Root Position

The secondary triads are built on the 2^nd scale degree (supertonic), 3^rd scale degree (mediant), 6^th scale degree (submediant), and 7^th scale degree (leading tone or subtonic).

Connecting root position primary and secondary triads

The connections between primary and secondary triads are governed by the intervallic movement of their roots.

The falling 5^th root progressions imitate the V – I resolution in a dominant-like manner.
The falling 3^rd root progressions extend the tonic (I – vi), subdominant (IV – ii), and dominant (V – iii) triads.
The rising 2^nd root progressions imitate the motion of IV – V.

Major

Minor

Falling 5^th

V – I

I – IV

ii – V

iii – vi

vi – ii

IV – vii^o *

vii^o – iii *

* as part of the diatonic sequence

v or V $\musSharp{}$ – I

i – iv

ii^o – v or V $\musSharp{}$

III – VI

III+ – VI

VI – ii^o

iv – VII

VII – III

mostly in natural minor

Falling 3^rd

I – vi

IV – ii

V – iii

vi – IV

I – iii (rising 3^rd exception)

i – VI

iv – ii^o

VI – iv

i – III (rising 3^rd in natural minor)

Rising 2^nd

IV – V

V – vi

iii – IV

I – ii (less frequent)

iv – V $\musSharp{}$

V $\musSharp{}$ – VI

III – iv

i – ii^o

The reverse of the above root movements is a retrogression and is used infrequently in music of the Common Practice. Modal music typically employs such backward movements.

common uses of secondary triads

The supertonic (ii) triad

Substitutes or prolongs the subdominant IV triad.
Normally resolves to V in a falling 5^th movement.

The submediant (vi) triad

Substitutes or prolongs the I triad. See the chapter on Deceptive Resolutions/Cadences.
Normally resolves to ii in a falling 5^th movement or to IV in a falling 3^rd movement.

The mediant (iii) triad

Substitutions: V – vi becomes iii – vi, and I⁶ – IV becomes iii – IV
Normally resolves to vi in a falling 5^th movement. Can also resolve to IV in a rising 2^nd movement.
In harmonic minor the III+ triad resolves to VI.

The leading tone (vii^o) and subtonic (VII) triad

The vii^o triad rarely appears in root position due to the doubled leading tone, except in the diatonic sequence where it does not function as a dominant-type chord.
In natural minor, the VII triad is a major triad. It typically resolves to III. The VII – III in minor sounds like V – I in the relative major, and often is employed by composers to hint at the relative major key while remaining in a minor key.

Voice Leading

Common tones

Roots a 5^th apart have one common tone; use common tone connection or contrary motion
Roots a 3^rd apart have two common tones; use common tone connection
Roots a 2^nd apart have no common tones; use contrary motion

Doubling

Primary and secondary triads in root position normally double the root (the bass).

1. Roots a 5^th apart (one common tone between chords)

(a) Common tone connection

*The irregularly doubled root in vii^o is acceptable if the chord is not functioning as a dominant. When used as a dominant type chord moving to the tonic, the vii^o chord is found in first inversion (see Secondary Triads in First Inversion).

When using ii^o – V $\musSharp{}$ in minor, avoid le moving up to ti, as it creates an unattractive melodic augmented second (A2). Instead use non-common tone connection.

(b) Non-common tone connection

2. Roots a 3^rd apart (two common tones between chords)

The primary triads are extended by their relative minor secondary counterparts.

3. Roots a 2^nd apart (no common tone between chords)

Imitates the movement of IV – V.

*In harmonic minor, V $\musSharp{}$ – VI in contrary motion produces an incorrect A2 between ti – le.

**The V $\musSharp{}$ – VI $^3_3$ with ti – do and re – do avoids the A2.

common progressions using secondary triads in root position

4. Descending major and natural minor tetrachord (d – t – l – s) harmonized

At cadences in natural minor, use the dominant chord from harmonic minor.

5. Descending major and natural minor scales harmonized with diatonic triads

6. Submediant to tonic

The tonic normally is followed by the functionally weaker submediant chord (I – vi or i – VI). Occasionally, however, the reverse occurs (vi – I⁶or VI – i⁶) with the bass moving from l(e) to m(e).

7. The Imperfect Circle of Fifths

The most common diatonic sequence is the falling 5^th progression that is transposed diatonically down by a step. (A sequence is a musical pattern, typically comprised of two chords, that is repeated on successive higher or lower pitches. After hearing two or three patterns, the sequence is recognizable.)

The result is a progression of chords based on consecutive falling fifths, creating the strongest harmonic movement in the tonal system.

The sequence is called the imperfect circle of fifths due the presence of the d5/A4 interval (tritone) between fa – ti.

Major

Minor

I – IV – vii^o – iii – vi – ii – V – I

do – fa – ti , – mi – la, – re – so, – do

i – iv – VII – III – VI – ii^o – V – i

la – re – so – do – fa – ti, – mi – la,

Chords are from natural minor except for the
final dominant chord from harmonic minor.

The bass line is a zigzag of falling fifths and rising fourths movements to avoid large skips in the same direction. Note the quasi “dominant” root motion and the sequential alternating of common and non-common tone connections. The root of the vii^o triad (ti) is doubled irregularly to maintain the sequential pattern.

The imperfect circle of fifths sequence can be translated into natural minor by considering the vi chord of the major key as the i chord in natural minor. Raise the leading tone of the V chord (si in la-minor) to produce a harmonic minor cadence. The syllables below utilize la-minor. (See discussion of la-minor in Diatonic Melodic Drills – La Minor.)

Note that in natural minor the VII, III, and VI chords produce a temporary touch of the relative major key.

A summary of short progressions that form the basis of much of tonal music

MAJOR

MINOR

I – IV – V – I

i – iv – V $\musSharp{}$ – i

I – IV – ii – V – I

i – iv – ii^o – V $\musSharp{}$ – i

I – vi – IV – V – I

i – VI – iv – V $\musSharp{}$ – i

I – vi – ii – V – I

or

iii – vi – ii – V – I

i – VI – ii^o – V $\musSharp{}$ – i

I – vi – IV – ii – V – I

i – VI – iv – ii^o – V $\musSharp{}$ – i

I – iii – IV – V – I

i – III – iv – V $\musSharp{}$ – i

i – III+ – VI – iv – V $\musSharp{}$ – i

I – V – vi – iii – IV – [ I $^6_4$ ] – V – I

i – v – VI – III – iv – [ i $^6_4$ ] – V $\musSharp{}$ – i

I – vi – iii – IV – ii – V – I

i – VI – III – iv – ii^o – V $\musSharp{}$ – i

Also see the chapters on Diatonic Sequences.

Practice 1

Secondary Triads in Root Position – Major

Secondary Triads in Root Position – Minor

Practice 2

Complete the left hand accompaniment by continuing the diatonic sequence. The pattern provided in the first two measures descends by step. Alternate common tone and non-common tone connection. The left hand is four-part harmony an octave lower and the right hand melody is an added fifth voice. Provide full analysis.

7 Secondary Triads in Root Position

Connecting root position primary and secondary triads

Major

Minor

common uses of secondary triads

Voice Leading

common progressions using secondary triads in root position

Major

Minor

A summary of short progressions that form the basis of much of tonal music

MAJOR

MINOR

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