Good ask.
I have never stopped to ponder that Lynn.
Probabbly more no vox songs in jazz than any other genre, and I note it is the only genre on soundclick that in fact has a sub genre for jazz vocals.
Me. I work on the theory if it sounds good, it is structured, and if not, it is not.
Nobody had ever gone so far as to even think of a genre like Adault Easy Listening when Jazz came alomng.
I still have trouble deciding if a piece i habve done , or am listening to is jazz, blues or sometimes even pop.
My Funny Valintine is jazz in my book.
And yep. How anything is done would decide what it is in that rendition than anything else.
Think of the band bluegrassing AC?DC stuff. Sure stops being rock and roll there but is still a lot of fun.
Graham

http://www.soundclick.com/bands/2/grahamhenderson_music.htm