A major chord (or a "major triad") is a chord composed of three notes, where the distance between the first and the second note is four semitones and the distance between the second note and the third note is three semitones.
The C major chord, for example, consists of the notes C, E, and G. There are four semitones between C and E. There are three semitones between E and G.
The major chord can also be described as composed of the major third and the perfect fifth of some scale. In the major scale in C, for example, the third note is E. E is a major third, because the interval between the first note C and E is four semitones. The fifth note on the scale is G. It is a perfect fifth, as the interval between the first note C and G is seven semitones.
Examples of scales with major chords
The following are examples of where the major chord occurs in common heptatonic scales.
- On the first note (the tonic), fourth note (subdominant), and fifth note (dominant) of the major scale (the Ionian scale). That is, if a major chord is composed over the first, fourth, or fifth note on the major scale, then all notes in that chord will also be on the major scale.
- On the third (the mediant), sixth (submedian), and seventh note (subtonic) of the minor scale (the Aeolian scale).
- On the fifth note (the dominant) and sixth note (submediant) of the harmonic minor scale.
- On the fourth note (the subdominant) and fifth note (dominant) of the melodic ascending minor scale.
- On the fifth note (the dominant) and sixth note (submedian) of the altered scale.
- On the first note (the tonic) and second note (the supertonic) of the Spanish gypsy scale.