The Most Up To Date Ruleset

Below is the most recent version of the ruleset.  I say most recent and not "finalised" as the ruleset constantly changes as I reharmonises new material.  This may be near the end of the project, though the ruleset may change long after the project is finished.

For official purposes, this can be seen as the final iteration of the ruleset within this academic project. Rather than have the rules labeled 1-2-3, etc, I've spit them into sections as per the older posts.  

These have come about as a result of trial and error; through studying theory textbooks, websites, online lessons, personal experimentation, lessons with my piano teacher, etc...

They have been selected as they are the ones I found to work in most circumstances.  Whereas other rules may have worked well in certain songs, many simply did not work for the vast majority of material I was working with.  As a result, this ruleset is significantly smaller and more concise than the first draughts I posted.  It is also a much simpler ruleset.  It got this way after I began reharmonising more and more tunes and began to realise what worked and what didn't.

While this means the resulting reharmonisations will be similar, it provides a good starting point for anyone wishing to reharmonise songs from scratch - which was the purpose of this project in the first place.  

I'm pleased to say that I've committed many of these rules to memory - I'm finding myself using them throughout my day to day playing, using them to explore harmonic options when performing, covering and composing songs.  Examples of the rulesets in use can be found throughout this blog.  More posts will be added in the coming days with recorded versions of songs reharmonised using the ruleset.

You can find the rules listed here in order of category.  Instead of having contextual rules in their own category I've added contextual notes under rules that they apply to.

Chord Extensions

1) If  chord is a simple triad, add the seventh relating to the key.  Eg. in key of C, C major can be come Cmaj7.  E minor can become Em7, G major can become G7, etc...

2) In most cases, simple triads can have the extended variations of their chords attached to them.  Eg. C major triad - add Maj 7, Maj 6, Maj 9, etc.

3) Major chords can be replaced with the relative minor chords: for example, Gmaj7 can become Em7, etc.

4) If the melody note does not fall on the fifth or perfect fourth, a flattened fifth can be added to a minor chord to create diminished colour.

TENSION NOTES - A list of notes that can be added sporadically to chords for colour:
ONLY ADD IF THE MELODY NOTE DOES NOT FALL ON A NOTE A SEMI-TONE APART FROM THE ALTERED NOTE

Major 6th - Add 9
Minor 6th - Add 9
Minor 7th - Add 9 or #11
Minor Major 7th - Add 9
Dominant 7th - add 9 OR b9, 11, #11, 13, b13
Minor 7th - add 9, 11
Minor 7th (lowered fifth) - 9, b13
Diminished 7th - Any note a whole step above a basic chord tone.

Chord Substitution

1) Dominant 7th chords may be replaced by minor seventh chords (eg. B7 can become Bm7) ONLY if the melody note does not fall upon the major third.  (This minor seven chord can then become the introduction to an imposed ii-V sequence).

2) Similarly, minor chords can be replaced with dominant seventh chords.  Same rules as above apply.

3) Any major triad can be made into a major 7 - those major 7 chords can then be replaced by the related mIII or mVI (eg. Cmaj 7 may be substituted for Em7 or Am7).

4) Those substituted chords may then be replaced by their major counterpart - e.g., Em7 may then become Gmaj 7.  Rule 3 can then apply to the same Gmaj7.  By doing this you can get a Bm7 chord from a Cmaj7 chord - MELODY DEPENDENT. 

5) If going into a ii-V especially, the ii chord can be substituted for a ii#9 b 5 chord.

6) You can change the chord a strong melody note falls on depending on the chord surrounding it.  For example, if you're in the key of C and the melody falls on a G, an A7 chord may be played over it due to the G being the seventh of A7.  Preferably the dominant chord will want to fall on a diatonic minor chord, such as Am7 or Dm7, etc...

Adding ii-V Sequences

1) A ii-V sequence can be added anywhere if the target chord is a major chord.  Eg, if the target chord is a Gmaj, Am-D7 can be added before the Gmaj.  

2) If there are multiple 4-5 sequences in a single line/passage, introduce a ii-V in the key of the 5.  Eg. in the key of D - if there's a G-A sequence, add an Em after the G leading into the A, leading to a G-Em-A sequence. 

3) Alternatively, replace the G with an Em, changing G-A into Em-A.

4) If there's a 1-4 (eg. F-Bb in the key of F), add a minor ii-v in the key of the 4.  Eg. F-Bb will become F-Adim7-D7b9 - Bb.  NOTE: DO NOT USE THIS MORE THAN ONCE IN A SINGLE VERSE/CHORUS OR IF THE MELODY FALLS WITHIN A SEMI-TONE ON EITHER SIDE OF THE GUIDE TONES OF THE ADDED CHORDS

5) Any dominant7 chord can have the minor seventh chord a fourth below placed before it.  Eg. A7 can have Em7 before it, or a Dm7 can be placed before a G7, etc.    

6) Any minor 7 chord can have the dominant seventh chord a fourth above it placed after it, for example B7 can be placed after any F#m7 chord, etc...

7) A ii-V can be added in the key above a target ii-V sequence.  Eg, if the target chord is Cmaj and the ii-V preceding it is Dm-G7, Em-A7 can be played prior to the Dm-G7 ii-V.

Tritone Substitution

1) Any dominant seventh chord can be replaced by it's tritone substitute if THE MELODY DOES NOT FALL WITHIN A SEMI-TONE OF THE CHORD'S GUIDE TONES.  Eg. G7 can become Db7/G, or G7/Db, etc...

2) Tritone substitution should be used sparingly.  Do not alter every dominant chord into it's tritone substitute.  The tritone substitute should be used for colour, especially near the end of lines where a resolution is likely.

3) ONLY WHEN IT DOES NOT CONFLICT WITH THE MELODY you may alter the tritone chord even more - instead of flattening the fifth and 9th, sharpen them and play them on top of the tritone.  Eg. F7-Bbmaj7  can become | B7/Db7 - Bb | (which is tritone/altered chord - Bb).  Again, this should only be used sparingly, preferably at the end of lines to build tension.