Diatonic Triads and 7th Chords AP Theory Diatonic Triads and 7th Chords
Diatonic Chords Diatonic – Chords that belong to a specific key/scale Altered/Chromatic Chords – chords using notes that are not part of a specific key
Minor Scale Issues The problem is the use of the raised 6 and 7 degrees according to where the line leads. There are many occasions where the melodic minor is used with the raised 6 and 7 leading upward by step and the lowered 6 and 7 leading downward by step Most of the underlying harmonies in minor conform to the harmonic minor scale (raised 7th degree)
Triads in Major Triads may be constructed using any degree of the major scale as the root These chords are named by the degree used as the root I, ii, iii, IV, V, vi, vii The triad type is indicated by the form of the Roman Numeral – uppercase, lowercase Diatonic Triads types in Major Major – I, IV, V Minor – ii, iii, vi Diminished – vii Augmented – none
Triads in Minor Because 6 and 7 are variable in minor, construction of these chords are more involved. Nonetheless there are 7 triads in minor that occur more frequently than the others – all belonging to the harmonic minor scale except the 5th of the III chord Diatonic Triad typed in minor Major – III, V, VI Minor – I, iv Diminished – ii, vii* Augmented – none
Seventh Chords in Major Seventh chord types Major seventh – uppercase roman numeral with a M7 Major-minor seventh – uppercase roman numeral with a 7 Minor seventh – lowercase with a 7 Half-diminished – lowercase roman numeral with a 7 Diminished – lowercase roman numeral with a 7
Diatonic Seventh Chords in Major M7 - I M7 and IV M7 Mm7 - V7 m7 - ii7, iii7, vi7 7 - vii 7 7 - none
Seventh Chords in Minor Because of the variable 6 and 7 degree there are 16 possible diatonic chords in minor The most commonly used seventh chords on each scale degree belong to the Harmonic minor scale Common Diatonic seventh chords in Minor M7 - III M7, VI M7 Mm7 - V7 M7 - i7 and iv7 7 ii 7 7 vii 7
Triads in Major and Minor
Diatonic Seventh Chords