1. Two common tones link the supertonic and the subdominant triads (Figure 8-1).
Figure 8-1. Common Tones, ii - IV
2. Triad Positions.
a. The supertonic triad is most frequently found in first inversion in both Major and minor keys (Figure 8-2).
Figure 8-2. Supertonic Triad in First Inversion
b. The supertonic triad in root position is less common than first inversion; however, it may be found in root position during a harmonic sequence (Figure 8-3).
Figure 8-3. Supertonic Triad in a Harmonic Sequence
c. Supertonic triads are not normally found in second inversions.
a. The third of the supertonic triad (subdominant scale degree) is normally doubled (Figure 8-4).
Figure 8-4. Doubled Third, ii6
b. The supertonic triad can occur in root position with the root of the triad doubled (Figure 8-5).
Figure 8-5. Doubled Root, ii
c. The fifth of the supertonic triad (submediant scale degree) is not normally doubled. In a minor key, the fifth of the supertonic triad is the altered sixth scale degree. Doubling the fifth makes resolution awkward (Figure 8-6).
Figure 8-6. Doubled Fifth, ii6 or iio6
4. Uses of the Supertonic Triad
a. Preparing the dominant. The supertonic triad is used to prepare the dominant triad (V), especially at a cadence. In minor, the instability of the diminished fifth drives it strongly toward the dominant (Figure 8-8).
Figure 8-8. Preparation of Dominant, ii6 or iio6
b. Preceding the cadential six-four chord. The supertonic triad precedes the tonic six-four chord at a cadence. The bass note leaps up a fourth. This is an exception to the rule that cadential six-four chords are approached by step (Figure 8-9).
Figure 8-9. Cadential Six-four
c. The supertonic triad moves to the diminished leading tone triad as a substitute for the dominant seventh chord at other than final cadences (Figure 8-10).
Figure 8-10. Leading Tone Triad
d. The supertonic triad is preceded by a subdominant triad (IV) or by a tonic triad (I) (Figure 8-11).
Figure 8-11. IV to ii or I to ii
|David L. Heiserman, Editor||
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Revised: June 06, 2015