Shop Tutorials Beginners Starter Pack CDsPPT mouthpieces

Jazz Reharmonising

Reharmonising – Changing the Chords

Often you may want to do some reharmonisation before arranging for jazz orchestra or combos. Most sheet music for popular music standards of the 30s, 40s and 50s will include chord symbols, but in some cases these will be wrong, too simple or too complex.

ReharmonisingSome publishers of sheet music invert a min7b5 so that it becomes a min6:


This is done to simplify the chord symbol for guitarists. The inversion makes no difference to the overall harmony if played alongside a bass instrument, but as a given chord symbol it implies the wrong bass note. A genuine m6 chord is usually either a tonic minor, or a IVm6 as part of a IV- IVm – I (plagal cadence). If it appears to be part of a IVm6 – V7 – I progression the chances are it is an inversion of II should be changed to IIm7b5 – V7 – I.

In mainstream jazz four note chords (7ths) are usual. Most sheet music will include four note chords (7ths and 6ths), but with other material (eg folk tunes) you will need to adapt triads according to the table below:

Major keys

Original triad Add 4th note Comments
I and IV major Major 7 Unless root is in melody
Major 6 Can use if root in melody.
Minor 7 Only for blues
V Minor 7
Minor Minor 7
Passing diminished Diminished 7 (= maj 6)
Diminished (chord VII) Minor 7 Minor 7 b5 (half diminished)

Minor keys

Triad 4th note Comments
Minor chord I Major 6 or 7 Can be dissonant or cheesy
Minor 7 Modal feel, may not always sound final
None Triad sometimes sounds best
Diminished chord II Minor 7 Minor 7 b5 (half diminished)
Major chord IV Major 6
Minor 7 Bluesy (can sound like dominant of bVII)
Minor chord IV Major 6 or minor 7
V Minor 7
Major chord bVI Major 7
Minor 7 Bluesy
Minor chord VI Minor 7
Major chord bVII Major 7 Dorian
Minor 7 Aeolian (beware, sounds like V7 of III major)
Minor chord VII Diminished 7
  • bVI is used to denote chord built on minor 6 degree of scale, eg Ab in key of Cm or F in key of Am.
  • A major or minor 6 chord does not have a 7th, otherwise the chord would be a 13th.

Did you enjoy this article? Please consider donating. All donations to charity Currently: £97500 so far! – INFO

Share on social media:
Sponsored ads