CONNECTING PRIMARY TRIADS
Primary triads in root position can be connected with few errors using the following
guidelines:

Place roots of triads in the Bass voice.
Keep the common tone in the same voice, then move the remaining two voices to the nearest chord tones by step (conjunct motion).

When there is conjunct root position movement, there is no common tone. In that case, move all upper voices contrary to the Bass to the nearest chord tones.

FIGURE 5.1: Connecting Primary Triads
DOUBLING
When writing triads in four parts, it is necessary to double one of the notes of the triad. Generally, double tonal notes. Modal notes may occasionally be doubled as a result of melodic line. In some instances it is necessary or desirable to triple the root and omit the fifth.

FIGURE 5.2: Doubling in Primary Triads
KEY ESTABLISHMENT
The primary means of establishing a key is to move from the major dominant triad to the tonic triad. The dominant triad in natural minor is minor. Therefore, the major form of the triad is borrowed from its parallel major key by raising the third with an accidental to create a leading tone and stronger resolution. This process creates the harmonic minor scale.

FIGURE 5.3: Major Dominant Triad in Minor
Use of the ascending melodic minor scale results in a major quality subdominant chord that may create a change of modality to major.