The answer to this question is "Major ninth on the dominant seventh chord V7 usually resolves Appoggiatura or the down by step going to the root of the dominant seventh". This V7 is frequently deleting the ninth functions on the chords as an upward resolving the issue and problem of Appoggiatura which is usually located on the third chord.
Because they both have a deep bass vocal
b. increased production of studs and spikes around the world
Alot of cultural things helped develope jazz especcially in new orleans where i recently was. most of the things that influenced jazz where the spirits of the people, wether sad or happy they always used jazz to show their spirits. but more things than feelings made jazz. you see jazz started around the time the french had gone into luisianna(sorry its spelled wrong) after they did the spanish forced their way into the new state and made everyone obey their rules. even though they followed those rules they still kept almost everything french made and french run but eventually people started mixing the instruments from spain and the instruments from france and learned how harmonic they sounded together eventually songs were made and the era of swing and jazz started not sure if i answered your question the way you wanted but hope this helps
