The Major Scale and Diatonic Chords
Every Note of the Major Scale relates to a Chord in a given Key. The C Major Scale spells the Notes C, D, E, F, G, A and B. In the Key of C, the Diatonic Chords are C, Dm, Em, F, G, Am and Bdim. Note that the I, IV and V Chords are always Major; and the II, III and VI always Minor. The VII is a Diminished Chord. A Triad is a 3-Note Chord, constructed with the Triad Formula of 1, 3 and 5. Play these Chords in the Key of C, and notice how well they relate to the Pitches of the C Major Scale; thus the reference to them as Diatonic.