Help: Origins of R&B's vocal technique [Jazz, Blues or independently evolved?]

Jazz student says she hates vocal runs/riff and Jazz Singer says "well it came from Jazz". Jazz Major begs to differ. Who's right?

http://imgur.com/a/u0kaO

This thread stumped me a bit and its referring to this vid that tackled the, "fat ladys sing better" myth (seems to be a comedy channel). The vid Featured a bunch of singers, and one particularly AWFUL singer here...people were claiming this "soul singer" was using jazz techniques....Then claimed those awful runs & riffs in R&B/soul somehow derive from Jazz.

Sorry, but my grandpa loved jazz but I distinctly remember him saying Nat King Cole and Frank Sinatra was "true pure Jazz". Personally, I can't stand the way R&B singers are all over the place and have to show off and over sing everthing. My grandpa who grew up on jazz, hated it too to. I dont know where it came from, but I really dont think Jazz had anything to do with it. Jazz was about grace, class and style.... not, whatever THAT mess is. The Jazz singer says she come from a "long line of Jazz singers"((eyeroll)) and therefor knows R&B came from Jazz. Sorry but I'm inclined to think a Jazz major would know better than some hand me down backwoods folktale.

TheJazz singer tries to gives examples of early vocal riffs/runs -

Mack the Knife - 0:40 and 1:22

How High the Moon - 0:35

Summertime - 1:10 and 2:15

But isnt claiming THAT technique led to R&B's elaborate vocals... just, jumping to conclusions? Those Jazz examples she gave are way more modest and tasteful. Isnt she just drawing connections where there are none? That lady even somehow claims, African-Americans need to know about "their heritage"....meaning, Jazz and Blues. ((eyeroll)) isnt Jazz and Blues AMERICAN heritage??? So now its "African American heritage"?? Americans invented Jazz, its AMERICAN culture. Seems to me, that Jazz singer is forcing this R&B - Jazz connection out of some sort of race agenda or something. And I dont buy anything shes saying but I can't find any info on how EXACTLY jazz is connected to R&B/Soul or where that R&B vocal style came from and its annoying as hell.

So what DID Jazz contribute to R&B, if anything at all. Anyone know?