In a minor key, all three primary triads (i, iv, v) are minor, giving the minor tonality its characteristic mellow, introspective mood

In a major key, the three primary triads (I, IV, V) are all major chords — giving the major key its bright, energetic quality. In a natural minor key, the three primary triads (i, iv, v) are all minor chords. In A minor: tonic = Am (i), subdominant = Dm (iv), dominant = Em (v). Because the primary triads are the most important chords in a key, the pervasive minor quality explains why minor tonality leans toward mellow, darker, introspective moods. When composers want a stronger V-i cadence, they use the harmonic minor (which creates a major V chord from sharpening the 7th).

Examples

A minor primary triads: Am (i), Dm (iv), Em (v) — all minor. Compare: C major primary triads: C (I), F (IV), G (V) — all major.

Assessment

Write out the three primary triads of E minor. Explain why they are all minor. How does the harmonic minor change the dominant chord?