WHAT IS THE SYSTEMATIC RE-HARMONIZATION OF A SONG BY GYPSY JAZZ?
IT IS THE RELATIVEZED HARMONIC REFINMENT.
RELATIVIZED HARMONIC REFINMENT=
1) We substitute a major chord X, with an harmonic pair (Y1,Y2) (harmonic pair means that Y1, Y2 have a distance at the roots an interval of 4th, that is Y1 resolves to Y2, so that usually Y1 is a chord with a 7nth)
2) and so that either Y1 or Y2 is relative to X (melodic relation which means the roots or middle note have a distance an interval of 3rd ) including the case Yi=X, and including 2nd relative (same root but the one major the other minor chord) ,
3) And the other chord to the relative can be major or minor.
An example is converting t he chord progression
4M 1M 5M7 1M as a cycle , to the gypsy jazz re-harmonized chord progression as a cycle
(2m, 5M7), (1M, 4maj7), (7dim7, 3M7) , (6m, 6M7).
(See also post 466)