The music composition questions tested in grade 8 music theory exam consists of harmony and chord progressions that contain unusual accidentals. The accidentals are added for specific reason and purposes. Below are the 10 types of altered chords that consists of unusual accidentals for special sound effects in music composition but they don’t indicate a modulation or change of key. These are chords which contain at least one foreign note or accidental and composers use it for changing of tone colour, not for modulation.
1. Supertonic Chromatic Chord: This is originally a supertonic minor chord, but the 3rd note of the chord is raised and hence it becomes an altered major chord. It can be identified as secondary dominants.
2. Neapolitan 6th: This is originally a supertonic minor chord, it is altered to be major chord that is built upon flattened 2nd note of the key and must be written as a first inversion chord. There are 3 steps to build this chord (eg.C major):
-flatten the 2nd note (Db) in C major
-build a major chord upon Db, hence it is Db, F, Ab
-this chord must be built in first inversion, hence it is F in the bass, followed by Ab and Db
3. Augmented 6th chords: It consists of augmented 6th and major 3rd intervals built upon flattened 6th note of the key. Forming a basic Italian 6th chord. When extra augmented 4th note is added on to the Italian 6th chord, it becomes French 6th. When perfect 5th is added on to the Italian 6th chord, it becomes German 6th chord.
Eg in C major:
-Italian 6th: the basic chord
-French 6th: the basic chord and the augmented 4th above the bass.
-German 6th: the basic chord plus the perfect 5th above the bass
4. Diminished 7th chord: This chord consists of 4 notes and all the interval between the notes are minor 3rds. This chord can be built upon #iii, #IV, #V, #Vi etc of the key. And it often consists of accidentals that are totally unrelated to the key.
5. Ib7: Chord I with flattened 7th note. Originated from chord I7, the 7th note of the chord is being flattened for special effect and colourful harmony. It is another altered chord, used chromatically for colour, not for modulation.
Following chords are ‘altered chords’, the sharpened notes need to be resolved one semitone higher and the flattened note of all the altered chords needed to be resolved one semitone lower when moving to the next chord.
6. I#5 augmented triad: Originated from major chord I, the 5th note of the chord is being sharpened hence it consists of 2x major 3rd intervals in this chord. Hence the original major chord has been expanded to become augmented chord sound, giving a surprising sound effect to the ears.
7. V#5 augmented triad: Originated from major chord V, the 5th note of the chord is being sharpened hence it consists of 2 x major 3rd intervals in this chord. Hence the original major chord has been expanded to become augmented chord sound, giving a surprising sound effect to the ears. The chords are not used in a minor key.
8. iib5: This chord is minor chord ii with a lowered 5th note of the chord and effective to be used in first inversion. Hence the original minor chord has been ‘shrunk’ to become diminished chord to create a extremely depressing sound effect.
9. IV: Originated from major chord IV of the major key, the middle 3rd note of the chord is flattened. Hence the original major chord IV become opposite minor chord due to the flattened 3rd note of the chord. It is the subdominant minor chord used in a major context.
10. bVI : Originated from minor chord Vi of the major key, the root and 5th notes of the chord are flattened. Hence the original minor chord Vi becomes opposite major chord due to the flattened 1st and 5th notes of the chord. It is actually the altered major chord on the lowered 6th of the key.
