Major triad

What it means

The major triad consists of root, major third, and perfect fifth; between third and fifth lies accordingly a minor third. In C major, C–E–G is the major triad on the tonic. It counts as consonant and at rest and is, together with the minor triad, the basic element of tonal harmony.

Musical use

Acoustically it is particularly deeply anchored: root, fifth, and major third appear low in the harmonic series, and the pure tuning of these intervals yields a sound in which the beats almost disappear. This explains its calm and its bright character.

In a major key, major triads stand on the first, fourth, and fifth degrees — that is, precisely on the principal functions tonic (I), subdominant (IV), and dominant (V). In minor a major triad occurs within the scale on the third, sixth, and seventh degrees of the natural form; the dominant is made a major sonority there by raising the seventh degree so that a leading tone arises. A major triad at the end of a minor piece is called a Picardy third.

A single semitone — the third — distinguishes it from the minor triad. This one note decides the mode and changes the effect completely. In four-part writing in root position the root is as a rule doubled; the third is doubled with restraint, because it easily stands out.

The major triad agrees with partials four, five, and six of the harmonic series, which has been cited since Zarlino and Rameau as the basis of its euphony. In chord symbols it is designated solely by the root letter, for instance C for the C major triad. In minor the major triad appears on the dominant through the raising of the leading tone, and also on the third and sixth degrees.

Performance practice

Intonate the major third lower than the piano plays it — in an ensemble this is the most effective single intervention for a calm sound. Balance the chord from below: root and fifth carry, the third colours. And practise distinguishing major from minor by ear deliberately on single chords.