The primary chords for any major key are the I, IV, and V chords of its corresponding major scale. For G Major the primary chords are: G, C, D, and D7.

A "Triad" is a three note chord. In traditional music theory, there are four triad chord types: major, minor, diminished, and augmented. Contemporary triads include sus and add.

A triad is a three note chord. In traditional chord theory there are four triad chord types: major, minor, diminished and augmented. This lesson covers the major and minor triads on string 1 2 3.

“G Major” (or the key of G) is a major scale based on G, with the pitches G A B C D E F#. Its key signature has one sharp: F#. Its Relative Minor scale is E Minor. Its Parallel Minor is D Minor.

The secondary chords for any major key are the II, III and VI chords of it’s corresponding major scale. For G Major the secondary chords are: Am, Bm and Em. From the primary and secondary chords of a major key countless songs and chords progressions can be played.