Chords in the key of C major (based on the C major scale). C major scale is C, D, E, F, G, A, B, C. Chord pattern for major scale is major, minor, minor, major, major, minor, diminished. Chords are C major, D minor, E minor, F major, G major, A minor and B diminished. Chords I, ii, iii, IV, V, vi and vii in the key of C on piano. | Piano-Keyboard-Guide.com