MODAL JAZZ COMPOSlTlON G HARMONY

But everything changes when degrees I and IV are treated as sev-enths, which is a quality only associated with the fifth degree in tonal harmony.This makes any hypothesis of assimilation impossible.The link between the function and the quality of a chord, which is organic in atonal situation, does not exist in blues. Indeed, let us look at the first degree withfour sounds: C-E-G-B b. All four notes belong to the scale as it has been defined.But this is neither true with the fourth degree (F-A-C-E b), as A does not belongto the scale, nor the fifth (G-B-D-F), which involves a B natural and a D that donot appear in the scale. This lack of organic link between the scale of referenceand how chords are built is a fundamental difference between blues and worksusing the tonal system.